Hawthorne was in charge of the Government of the Starship UK, put in charge under the Queen at the time. He was responsible for making the Smilers, a race of androids that were used to police the Starship UK, and turning the space station into a police state. He believed this was necessary for the continuation of the Starship. It was him who directed the Star Whale through torture.
While he initially seemed to have usurped control from the Queen, he was revealed to have been acting under her original orders in regards to the Whale. Every time Liz came close to the truth, he would take her to the Tower of London and reveal the whole truth to her, giving her a choice about whether to wipe her mind or release the whale. The Doctor uncovered the situation and Amy Pond concluded that the Whale would direct Starship UK without torture, a fact that stunned Hawthorne. (DW: The Beast Below)