The Eleventh Doctor was a capricious and adventurous incarnation of the renegade Time Lord known as the Doctor. The Moment referred to him as "the man who forgets", in reference to his claim not to remember how many children were on Gallifrey on the last day of the Last Great Time War. He later became a man fond of remembering his precious life. However, by this point in his life, his reputation had grown immense, attracting a new strain of conflicts in place of the war. Wishing to withdraw from the dangers it created, he became a secretive and guileful individual for the sake of himself and those he held close. He engaged in a centuries-long struggle to the death against his enemies, including an assassination plot and a last stand. He was easily the Doctor's most long-lived known incarnation, as well as the final incarnation of his original regeneration cycle.

Within minutes of his fiery regeneration, he began a long, multi-century war with the Silence that critically involved companions Amy Pond, Rory Williams and their daughter, River Song. Ultimately, the significant, but likely not total, defeat of the Silence required him to marry Song in a dubiously legal ceremony,  but one that they both seemed to regard as genuine.

After the touch of a Weeping Angel robbed him of Amy and Rory, he retired to Victorian London and associated himself with the "Paternoster Gang". During this period — which he once referred to as "the dark times" — he rediscovered a woman named Clara Oswald, whom he thought long dead; she once again died. Fascinated by this "impossible girl", he set off to solve the mystery of her multiple lives, and take her on as his latest travelling companion. He discovered her to be part of his time line, having entered it in order to save him from the Great Intelligence. In doing so, he revealed to her his secret incarnation, who fought in the Time War.

With his tenth incarnation, he re-entered the Time War where he discovered that he and his past incarnations had actually saved the Time Lords from destruction, but lost knowledge of the event. This allowed him to cleanse his hands of a genocide he never actually enacted and happily accept the incarnation he once renounced.

He spent his later life battling against the universe's deadliest forces to protect the planet of Trenzalore for hundreds of years, causing his body to grow old and weak. At the cusp of dying of old age, Clara convinced the Time Lords to grant him a new regeneration cycle, restoring his youth and triggering his eventual regeneration into his next incarnation and changing his future.

_{Biography from the TARDIS Data Core article, licensed under CC-BY-SA}

Companions:

Amy Pond, Rory Williams, River Song, Craig Owens, Clara