Sycorax invasion of Earth

From Tardis Wiki, the free Doctor Who reference
"Sycorax invasion of Earth" is a title based upon conjecture.

Check the behind the scenes section, the revision history and discussion page for additional comments on this article's title.

The Sycorax invasion of Earth was an attempted invasion of Earth on 24 December to 25 December 2006 by the Sycorax in order to turn half of the human population into slaves via forcing surrender through blood control. The invasion was stopped by the Tenth Doctor when he defeated the Sycorax leader in combat. After Prime Minister Harriet Jones ordered the destruction of the retreating Sycorax spaceship, the Doctor organised her downfall in retaliation. (TV: The Christmas Invasion)

History

Origins

During the Slitheen crisis, the MP for Flydale North, Harriet Jones, emerged as a leader in dealing with the situation. Following the defeat of the Slitheen, the Ninth Doctor encouraged Harriet to run for Prime Minister, aware that history stated that Harriet would become Prime Minister for three consecutive terms and create Britain's Golden Age. (TV: Aliens of London, World War Three) Following this, Harriet was eventually elected Prime Minister in a landslide majority and under her leadership, Britain did in fact begin going into what many were calling a Golden Age. A project undertaken by Harriet's administration was the Guinevere One space probe launched to explore the Martian surface. However, the probe was intercepted and captured in orbit of Mars by the Sycorax spaceship. (TV: The Christmas Invasion)

During a conflict with the Daleks, the Ninth Doctor absorbed the energy of the Time Vortex in order to save his companion Rose Tyler. As such, he regenerated into the Tenth Doctor. (TV: The Parting of the Ways) As Rose was shocked by this new incarnation of the Doctor, he agreed to return her home at Christmastime. (TV: Born Again) However, the Doctor's regeneration was not complete and he collapsed until his body had finished changing fully. As such, he was bed ridden, cared for by Rose in her mother's flat. While the Doctor was unconscious, he released regeneration energy that travelled into space. (TV: The Christmas Invasion)

Invasion

Roboform attack

While Christmas shopping with her boyfriend Mickey Smith, the Doctor's companion Rose Tyler came under attack by Roboforms. Fleeing in a taxi, Rose realised that the Roboforms were after the Doctor as he was the only thing they had worth being attacked for. Rose attempted to contact her mother to warn her, but Jackie was too busy talking on the phone to take the call. Unnoticed by anyone, the unconscious Doctor continued to release regeneration energy from his mouth into space.

Upon returning home, Rose attempted to take her mother and Mickey somewhere safe before she noticed a Christmas tree that had not been there when she left. After no one could account for the tree's existence, it came to life and attacked them. Unwilling to abandon the Doctor, Rose desperately attempted to wake him up to help. As the tree entered the room, the Doctor finally awoke when Rose pleaded for help in his ear. The Doctor destroyed the tree using his sonic screwdriver and recognised that it had been remote-controlled.

The Roboform prepares to attack. (TV: The Christmas Invasion)

From the balcony of Jackie's flat, the Doctor observed the Roboforms on the street nearby. After the Doctor raised the sonic screwdriver at them, the Roboforms transmatted away. Though Mickey believed the threat was over, the Doctor called the Roboforms "pilot fish" before he collapsed with pain. The Doctor warned that he had been awoken too soon and was still regenerating. As a result, the Doctor was "bursting with energy" that the pilot fish could smell, demonstrated by the Doctor expelling more regeneration energy from his mouth. Just before the Doctor experienced a neural implosion and lost consciousness again, he warned Rose that the pilot fish's presence meant that something bigger was coming. (TV: The Christmas Invasion)

First contact

Mickey researched pilot fish on the Internet and discovered them to be scavengers as the Doctor had stated. However, Mickey also discovered that pilot fish swam alongside bigger fish such as sharks which meant that something worse than the Roboforms was coming. Since "the pilot fish don't swim far from their Daddy," Rose and Mickey realised that whatever else was coming was close.

As Mickey researched pilot fish, Jackie turned on a news report about the Guinevere One which Daniel Llewellyn and his team had briefly lost contact with and which was about to broadcast its first images from the Martian surface. As Rose and Mickey discussed what Mickey had found on the Internet, Jackie drew their attention to the news report where a snarling Sycorax was broadcast from Guinevere One.

As the world reeled from absolute proof of the existence of alien life, Daniel was transported to a UNIT command centre beneath the Tower of London where he met with Prime Minister Harriet Jones. Though Harriet had a story put out that the transmission was a hoax, she recognised that it was in fact real and sent by a species unlike any that had ever been encountered before.

Harriet was brought to Sally Jacobs who reported that the transmission was not from the Martian surface but five thousand miles above the planet which meant that the Sycorax had a ship which the probe was on board of. Major Blake theorised that the alien ship was simply in flight when it came across the probe. Sally reported to Harriet the fact that the ship was on the move towards Earth "very fast."

As UNIT and Mickey, having hacked into UNIT, monitored the approach of the ship, the Sycorax broadcast a message to Earth that was incomprehensible to everyone listening to it. Major Blake ordered Alex to work on using translation software to decode the message while Rose was disturbed that she couldn't understand the Sycoraxic since the TARDIS translation circuit automatically translated every language inside of her head. A worried Rose theorised that it was due to the Doctor's current condition that the translation circuit wasn't working for her. As time went on without the Doctor waking up to help, Rose became more and more concerned, convinced that the old Doctor would've woken up and saved them.

With the Sycorax ship about five hours away, Harriet refused demands from the United States President to be given command, NATO forces went on high alert and Alex struggled to decipher the Sycorax message. After being told that there was no sign of the Doctor, Harriet asked Major Blake if Torchwood could do anything to help the situation despite the fact that Harriet was not supposed to know about Torchwood. Although Major Blake had reservations, Harriet ordered him to contact Torchwood for help and he reluctantly complied.

Finally, Alex managed to decipher the Sycorax message: "people (or possibly cattle), you belong to us, to the Sycorax. We own you. We now possess your land, your minerals, your precious stones. You will surrender or they will die. Sycorax strong, Sycorax mighty, Sycorax rock!" Though confused by the Sycorax using the pronoun "they" instead of "you," Harriet ordered that Sally respond to the message: "this a day of peace on planet Earth, we extend that peace to the Sycorax. This planet is armed and we do not surrender." (TV: The Christmas Invasion)

Blood control

As dawn rose over Great Britain, the Sycorax finally responded As everyone in the Tower of London watched, the Sycorax leader extended his hand towards the screen and it began glowing blue. Once he had done so, people all around the world, including Sally Jacobs, glowed with the same blue energy and came under his control. In a trance-like state, the afflicted people made their way onto the highest rooftops that they could find with friends and loved ones desperately trying to stop them to no avail. Finally, all of the afflicted people came to a stop on the edge of the roofs where they could be forced to jump to their deaths.

Harriet Jones pleas for the the Doctor's help. (TV: The Christmas Invasion)

Unaffected, Daniel realised that this was what the Sycorax meant: surrender or everyone under the Sycorax's control would die. Alex reported to Harriet that not everyone was affected, only about one-third of the population of Earth, (TV: The Christmas Invasion) over 2000000000 people. (PROSE: Alien Life) However, this left approximately two billion people poised to jump to their deaths if so ordered by the Sycorax. Harriet was informed by Major Blake that while Torchwood had what they needed, Torchwood had also lost one-third of their staff to the Sycorax control and needed more time to be ready. At the same time, Alex realised that everyone affected was from family lines such as siblings and parents and children, but no husbands and wives. After checking the personnel records of everyone from UNIT who was affected, Daniel discovered that they all had an A+ blood type. As part of Guinevere One, Daniel had included a vial of A+ blood which the Sycorax were now using to their advantage.

With the situation growing ever more dire, Harriet decided to make an emergency broadcast in place of the Queen's speech, urging everyone to remain calm. In her broadcast, Harriet pleaded for the Doctor's help or for anyone who knew the Doctor to find him to help in the grave situation. With the Doctor still unconscious, Rose accepted the fact that the Doctor she knew was gone completely. (TV: The Christmas Invasion)

Unbeknownst to the Prime Minister, her televised message had been intercepted and played on the TARDIS scanner used by the Third Doctor while he was working at UNIT HQ over thirty years prior, assisted by Jo Grant and Captain Mike Yates. Though the message was faint at first, the earlier Doctor was able to uncover it using a device he had created. Jo was quick to suggest that they go and help, though she did speculate that the Master had travelled forwards in time and hypnotised Harriet to lure the Doctor into a trap. The Doctor, however, did not believe so as he felt a connection linking him to Harriet, unsure as to whether it came from his future or his past. Intending to find out what was going on, the Doctor took his TARDIS into the future, taking Jo and Yates with him. (PROSE: The Christmas Inversion)

Negotiations

Suddenly, a sonic wave shattered every window for miles around as the Sycorax spaceship entered the Earth's atmosphere and came to a stop over London. With the situation seemingly hopeless, Rose ordered her mother to gather supplies and that they would retreat with the Doctor to the TARDIS, the only safe place on Earth. Though reluctant, Jackie agreed to flee into the TARDIS.

After arriving over Earth, the Sycorax contacted UNIT and demanded, as translated by Alex, that the leader of the world step forward. Harriet stepped forward to represent Earth and Harriet, Major Blake and Alex were transmatted aboard the Sycorax spaceship where the Sycorax leader removed his helmet to greet them.

Holding his hand over the button controlling the people under his control, the Sycorax leader demanded Earth's surrender or he would force the afflicted people to jump to their deaths. Blaming himself for the events, Daniel Llewellyn stepped forward and attempted to convince the Sycorax leader to show the human race compassion. In response, the Sycorax leader used his death whip to burn Daniel into a skeleton with Major Blake suffering the same fate when he protested Daniel's murder. Harriet stepped forward as the Prime Minister and the Sycorax leader, through Alex's translation, demanded once more that Harriet surrender or the afflicted people would die. "One-half is sold into slavery or one-third dies. Your choice."

Harriet and the others confront the Sycorax leader. (TV: The Christmas Invasion)

At the same time, Rose and Mickey dragged the Doctor to the TARDIS as Jackie attempted to bring massive amounts of food despite Rose's orders to leave it behind. On board the TARDIS, with Rose unable to fly it, Jackie went back for more supplies and Mickey attempted to activate the TARDIS scanner to learn what was happening.

Unknown to Rose and Mickey, their attempt to activate the scanner resulted in the TARDIS being detected by the Sycorax. Enraged and believing that the humans were hiding foreign machinery from them and conspiring with someone, the Sycorax leader ordered the TARDIS transmatted aboard his ship. As Jackie returned with more supplies, she helplessly watched the TARDIS being transported away.

Unaware that they had been transported away from Earth, Rose got worried about her mother's safety and went to help, only to discover the interior of the Sycorax ship. As Rose was escorted away, her screams drew Mickey's attention which caused him to rush to Rose's aid. Upon emerging from the TARDIS, Mickey was shocked to discover the Sycorax ship as well, but managed to shut the TARDIS door before being captured after being ordered to do so by Rose. (TV: The Christmas Invasion)

Blast from the Past

In his third incarnation, the Doctor received foreknowledge of the Sycorax invasion while his future self made the fateful confrontation. (PROSE: The Christmas Inversion)

Shortly after the TARDIS was taken by the Sycorax, the earlier version of the TARDIS, containing the Third Doctor, Jo Grant and UNIT Captain Mike Yates landed on the Powell Estate. Before disembarking, the Doctor found that his regenerative energy was being drained, which Jo suggested was the work of the Master. However, the Doctor realised that a future version of himself was present in this time, and was in need of the energy. Moments later, the strain on the Doctor passed just before he and his companions were confronted by Jackie Tyler. As he introduced himself, Jackie adopted the mistaken assumption that this Doctor was the next form of her Doctor, and that Jo and Yates were the new forms of Rose and Mickey.

Realising that Jackie was familiar with himself and the TARDIS, the Doctor inquired as to the message still playing on his scanner, learning from Jackie that the message came from Harriet Jones, the Prime Minister of the United Kingdom with whom he would save the world, leading to Britain's Golden Age. Jackie soon directed the three to the Sycorax ship in the sky, as well as the blood controlled masses standing on the rooftops. As Jackie observed that the Doctor was "awake again", he reasoned that his other self was suffering from a regeneration crisis before deciding that they needed to find Harriet Jones. Following this, the Doctor came under attack from a sprig of "murderous mistletoe" which had been left behind by the Roboforms, but was saved by Jackie, who had suggested that Harriet would be found at UNIT HQ. By consulting Jackie's laptop, the Doctor learnt that UNIT's headquarters was now located within the Tower of London.

Taking another trip in the TARDIS, the Doctor and his companions arrived within the grounds of the Tower, where they were stopped by a beefeater standing near Traitors' Gate. Though the beefeater was well aware of the Doctor and UNIT, the Doctor was unable to convince him of his identity as he found that his UNIT pass had expired thirty years prior. (PROSE: The Christmas Inversion)

The Doctor awakens

Unnoticed by Mickey, in his hurry to help Rose, he spilled some of Jackie's tea near the still-unconscious Doctor. The tea spilled onto the circuitry under the console room floor which resulted in it heating up and becoming steam which the Doctor inhaled at which point the Doctor released more regeneration energy.

On the Sycorax ship, Rose was reunited with Harriet and informed Harriet that they were on their own. Since Rose had the TARDIS, the Sycorax leader demanded that she speak on behalf of the Earth. Declaring that "someone's got to be the Doctor," Rose decided to represent the Earth despite Mickey and Harriet's objections due to the risk of her safety. Citing all of the races she had encountered, Rose attempted in vain to order the Sycorax to leave, but only succeeded in amusing them.

As the Sycorax leader taunted Rose as he prepared to kill her, his words unexpectedly became understandable to all of the humans gathered. With the Sycorax leader angrily insisting that he was only speaking Sycoraxic, Rose realised that the TARDIS translation circuit was working once again which meant that the Doctor had been restored. Moments later, the Doctor emerged from the TARDIS, disarmed the Sycorax leader of his whip and broke his staff. The Doctor explained that the "superheated infusion of free radicals and tannin" from Jackie's tea had healed the Doctor's synapses and allowed him to awaken. The Doctor asked Rose about his new appearance following his regeneration and convinced Harriet of his identity using information from the time that they were trapped in 10 Downing Street together. (TV: World War Three)

The Sycorax leader interrupted the Doctor's reunion with his friends, demanding to know who the Doctor was. As the Doctor mused on who he was, he noticed the Sycorax control matrix with its "great, big threatening button." The Doctor examined the control matrix and after he discovered the A+ blood, realised that the Sycorax were using blood control on the all of the A positives on Earth. Despite the protestations of everyone present, the Doctor pressed the button. However, instead of killing everyone, the Doctor's actions resulted in them taking a step towards the edge of the roof before the Sycorax control over the afflicted people suddenly broke. (TV: The Christmas Invasion) This was witnessed by the Third Doctor and his companions as he attempted to get past the beefeater at the Tower of London. (PROSE: The Christmas Inversion)

Though the Sycorax leader attempted to claim that the Sycorax allowed the people to live, the Doctor called blood control "a cheap bit of voodoo." As a result, like hypnosis, you couldn't hypnotise a person to kill themselves due to people having too strong of a survival instinct. Despite the blood control being broken, the Sycorax leader threatened to call in the Sycorax Armada to take the Earth by force. (TV: The Christmas Invasion)

Duel

Drawing a sword from one of the Sycorax warriors, the Doctor challenged the Sycorax leader to a duel under the sacred rules of combat to determine the fate of the planet. The Doctor and the Sycorax leader dueled throughout the room and onto the wing of the ship with the Doctor outmatched. Though Rose tried to help, the Doctor ordered her not to as it would invalidate the challenge. Subsequently, the Sycorax leader knocked the Doctor to the ground "like a lowly dalskaak" at the edge of the ship and cut off the Doctor's hand, sending it and the sword to the city below.

The Tenth Doctor battles against the Sycorax leader. (TV: The Christmas Invasion)

Getting up, the Doctor revealed that he was within the first fifteen hours of his regeneration which left the Doctor with enough residual regeneration energy to grow a new hand. Now convinced that he was really the Doctor, Rose tossed the Doctor another Sycorax warrior's sword to continue the fight. With his new "fighting" hand, the Doctor overpowered and disarmed the Sycorax leader. Holding the Sycorax leader at sword-point, the Doctor offered to spare his life if the Sycorax leader would swear on the blood of his species to leave and never returned, something the Sycorax leader complied with.

Happy, the Doctor discarded the sword and made his way back to the interior of the ship. However, the Sycorax leader retrieved the Doctor's discarded sword and attempted to attack the Doctor from behind. The Doctor hit the Kojux-flap near the door with a satsuma found in his bathrobe which caused a flap to open on the wing of the ship under the Sycorax leader's feet. As the Sycorax leader fell to his death miles below, the Doctor declared: "No second chances. I'm that sort of man."

Having won the duel, the Doctor entered the main chamber and, by the ancient rites of combat, forbade the Sycorax to scavenge on Earth for the rest of time. The Doctor ordered that when the Sycorax returned to the stars and spoke of humanity and planet Earth, that they spread the word that "it is defended." Defeated, the Sycorax transmatted the Doctor, Rose, Mickey, Harriet and Alex to the ground on Bloxham Road. (TV: The Christmas Invasion, PROSE: The Final Darkness)

Meanwhile, the Third Doctor, through a monitor screen carried by the beefeater, saw his future self as pointed out by Jackie Tyler on Bloxham Road before taking her back to her flat. There, they found the Master, who was restrained by the tinsel which accompanied the Roboform Christmas tree. Clarifying to Jo that he was not "behind it", the Master confessed that he did follow the Doctor to the time of the invasion, where he had intended to ally with the Sycorax so he could enslave the Earth himself, only to have spent the past hour within the flat, having been captured by the tinsel after arriving in his TARDIS, which took the form of a fridge. On this occasion, the Doctor deemed that the Master had "suffered enough" and so set him free to leave in his TARDIS. (PROSE: The Christmas Inversion)

Having seen the Master off, the Doctor called his companions back to the TARDIS. Though Jo pointed out the spaceship still in the sky, the Sycorax proceeded to depart with their ship taking flight as she spoke. (PROSE: The Final Darkness, The Christmas Inversion, TV: The Christmas Invasion)

Torchwood attacks

As Rose and Mickey celebrated, Harriet was pleased to recognise that the new Doctor was exactly the same man as she once knew. The Doctor warned Harriet that there were many more races out in the stars noticing Earth now because of all the "noise" that the human race was making with their signals and probe. "You better get used to it," the Doctor warned a visibly worried Harriet.

As the Doctor, Rose and Mickey reunited with Jackie and celebrated their victory, Alex brought Harriet word from Torchwood that they were ready to fire. After looking at the Doctor and his friends for a moment, Harriet gave the order to do so. Torchwood fired upon the Sycorax spaceship with the laser weapon from a Jathaa sunglider, destroying the retreating ship in space.

Among the Sycorax aboard the ship was a scribe who was recording the events of the invasion. In their last seconds, the scribe defiantly told the assembly in the Hall of War Pacts that the Sycorax shall fill the darkness and the scent of their blood shall be scented by the Sycorax Armada after the burning of the Sycorax's hearts to attack Earth. (PROSE: The Final Darkness)

At 48 Bucknall House, the destruction of the Sycorax ship was witnessed by Jo, who still suggested to her Doctor that they stay to check on Rose as well as his future self. The younger Doctor, however, was quick to dismiss this prospect as he returned with her and Yates to UNIT HQ, over thirty years in the past. (PROSE: The Christmas Inversion)

Back on Earth, an enraged Tenth Doctor confronted Harriet, declaring thst she murdered the Sycorax. A remorseless Harriet claimed that it was defence using alien technology adapted from a ship that had fallen to Earth ten years before. Harriet insisted that the human race needed to be able to defend itself, especially as the Doctor was not always there to help as he was not for most of the invasion. With Harriet refusing to concede that she made a mistake, the Doctor claimed that he could bring down Harriet's government with just six words which he whispered to Alex: "don't you think she looks tired?" As the Doctor and his friends departed in disgust, Harriet panicked about the Doctor's words before quietly apologising for her actions. (TV: The Christmas Invasion)

Aftermath

The Doctor and Rose in the "snow" left by the destruction of the Sycorax ship. (TV: The Christmas Invasion)

Following the failed invasion, the Doctor stated that the people of Earth could no longer deny the existence of alien life in the universe and called it "a whole new world." (TV: The Christmas Invasion) UNIT issued a press briefing where they confirmed the existence of aliens, and said that they will be waiting for Earth's next visitors, to offer friendship or to challenge them. (PROSE: Alien Life) Jack Harkness would use the Sycorax spaceship as well as the later Battle of Canary Wharf as proof while discussing aliens with Gwen Cooper. However, it was apparent that some remained unconvinced, with Gwen noting that her boyfriend Rhys Williams believed that drugs in water supplies had caused mass hallucinations, a theory which Jack called "stupid". (TV: Everything Changes)

The Doctor stopping the invasion convinced Rose Tyler that he was indeed the same man she knew and she chose to continue on as the Doctor's companion. After choosing a new attire from the TARDIS wardrobe, the Doctor had Christmas dinner with Rose, Mickey and Jackie that Christmas night. (TV: The Christmas Invasion)

Meanwhile, many Londoners went to Trafalgar Square, among them were members of the group that would later be called LINDA. Ursula Blake recalled that "everyone was celebrating just being alive". The Doctor observed these celebrations where, unbeknownst to him, he was caught in one of many the pictures taken by Ursula, who did not realise his significance until fellow LINDA member Colin Skinner pointed him out. Ursula then posted the image of the Doctor online to her blog, My Invasion Blog.

In light of the invasion, the internet went "into meltdown" as Elton Pope discovered when he attempted to research it online. Eventually, however, Elton discovered the image of the Doctor, who he recognised from an encounter in his childhood, on Ursula Blake's blog. This led Elton to make contact with Ursula, joining her group of friends who shared an interest in the Doctor, with Elton naming the group LINDA. (TV: Love & Monsters)

A Sycorax sword was recovered and taken to the Leamington Spa Lifeboat Museum before being destroyed by a robot controlled by Mickey Smith. (GAME: Security Bot)

As "Harold Saxon", the Saxon Master took advantage of the vacuum left by Harriet Jones' downfall. (TV: The Sound of Drums)

Thanks to the Doctor, Prime Minister Harriet Jones began facing rumours of ill health and a possible vote of no confidence. (TV: The Christmas Invasion) Harriet would later confirm that the Doctor did effectively depose her. (TV: The Stolen Earth) As a result, Britain's Golden Age as predicted by the Doctor ceased to exist and the way was opened for the Saxon Master to take power as Harold Saxon. Following his election in 2008, "Saxon" cited the "spaceship over London" as an example of an alien event which the British government failed to disclose to the public. (TV: The Sounds of Drums) (TV: The Sound of Drums)

Standing by her beliefs, Harriet Jones would give her life to help save the Earth. (TV: The Stolen Earth)

On a personal level, following her disposal, Harriet went on to work with the Mr Copper Foundation to develop the subwave network to contact the Doctor in case he was ever needed. Before giving her life during the 21st century Dalek invasion, Harriet stated that she had reflected upon her decision to murder the Sycorax after being deposed by the Doctor and ultimately stood by it as she was right in the fact that the Doctor was not always there when planet Earth needed his help. (TV: The Stolen Earth)

As a result of the appearance of the Sycorax ship above London, followed by the Webstar's attack on the city on Christmas Eve of 2007, London was deserted for Christmas in 2008. Two holdouts were Wilfred Mott and Queen Elizabeth II. (TV: Voyage of the Damned)

The wives of the Sycorax killed in the invasion would seek revenge for the loss of their husbands. (COMIC: The Widow's Curse)

When the Sycorax wives went looking for their husbands in the Sol system following the failed invasion of the Fadros Pallujikaa's ship in 2006, they found nothing but the dust remains of the ship. They landed their own ship in the Caribbean, disguising it as an island called Shadow Cay, which became populated by humans turned into zombies, known as abstracts, by the Gilfane Craw. The abstracts were used to find the black box recorder the Foraxi Yox so they could discover the truth of what happened to the Sycorax on the first ship. In 2009, the abstracts salvaged the Foraxi Yox. When it was played back, the Haxan Craw realised that the humans betrayed the Sycorax. The aeroplane containing the Gilfane Craw's phage abstracts that would spread a virus leaving humanity suffering but unable to die were brought aboard a stolen aircraft, but Donna Noble and Norah stowed away on board and flew the plane back to Shadow Cay. The Tenth Doctor, controlling the abstracts on the ground, overloaded the ship's magma-sculptor by making it attempt to copy the whole of Earth, and caused the ship to begin to take off. (COMIC: The Widow's Curse)

Years later, the Twelfth Doctor would meet the Sycorax Kraxnor, who blamed him for the destruction wrought on his people. (COMIC: Ghost Stories)

The Meta-Crisis Tenth Doctor owed his existence to the loss of the Tenth Doctor's hand. (TV: Journey's End)

The hand the Doctor lost during his fight with the Sycorax leader was recovered by Captain Jack Harkness who kept the hand in the Torchwood Hub. (TV: Everything Changes) Following The Year That Never Was, the Doctor recovered the hand and kept it in his TARDIS. (TV: Last of the Time Lords et. all) After being mortally wounded by a Dalek, (TV: The Stolen Earth) the Doctor channeled his regeneration energy into the hand to avoid changing again. As a result, when Donna Noble touched the hand, it became the Meta-Crisis Tenth Doctor. (TV: Journey's End)

The Great Intelligence mentioned, among others, the death of "the leader of the Sycorax" at the hands of the Doctor to dispute Madame Vastra's claim that the Doctor was never "blood-soaked". (TV: The Name of the Doctor)

Parallel universe

In a parallel universe, Rose Tyler found that the invasion never occurred. (AUDIO: The Endless Night) She later determined that the invasion did not occur in at least one other universe. (AUDIO: The Last Party on Earth)