Web of Time

The Web of Time or Spiral Politic was the orderly co-existence of events within Time.

It was not a necessary fundamental of the universe, but rather a meta-structure created and imposed on history by the Time Lords (BFA: Neverland, FP: The Cosmology of the Spiral Politic). It could not exist until Rassilon built the Eye of Harmony and used it as what has been described as "the hitching post of chronology" (BFA: Neverland) or "the anchor of the thread." (FP: The Book of the War)

With the Web in place, the otherwise fragmentary nodes of history were connected into one structure (FP: The Book of the War). Yet it was not invulnerable; for example, the Sixth Doctor once explained that to destroy the planet Earth in 1985 would disrupt the Web of Time (DW: Attack of the Cybermen). The maintenance of this Web was one of the primary functions of the Time Lords, and a duty which the Doctor regarded with grave seriousness. A backup of the Web of Time was stored on Shada, which stood outside of time so that it could be remapped onto the universe if ever time was altered. (FP: A Labyrinth of Histories)

The Doctor, then in his first incarnation, may have meant this when he stated to Barbara Wright that she could not change history. (DW: The Aztecs)

During the first battle of The Second War in Heaven on Dronid, should it have taken place, the Time Lords would have discovered that The Enemy had constructed their own Web of Time to replace the Time Lord meta-structure in the Universe. (FP: The Book of the War)

Since the Daleks proved capable of manufacturing their own Eye of Harmony (BFA: The Time of the Daleks), they may also have been able to set up a hostile Web of Time during the Last Great Time War.

In the Post-Gallifrey universe, the Web may have gone the way of its creators, as history was now constantly in a state of flux and revision (DW: The Unquiet Dead). Worlds might quite plausibly be destroyed before their time, (DW: The Shakespeare Code) and whole eras of history, such as the Fourth Great and Bountiful Human Empire (DW: Bad Wolf), and the later two terms of Harriet Jones, briskly unwritten. (DW: The Christmas Invasion)

The stable fixity of the Web of Time appeared to have given way to a more mutable and dangerous "Timey-wimey" structure. (DW: Blink)

The state of flux, possibly caused by the absence of the Web, allowed for time to be rewritten (DW: Flesh and Stone) due to cracks in the universe caused by the explosion of the Doctor's TARDIS. (DW: The Pandorica Opens)