Anacletos

Anacletos was an orphan sold into slavery as a gladiator. His skills were recognized by the Templars, who soon recruited him to their cause. He hunted his targets with dedication and ferocity.

In 2012, his genetic memories were used by the Templar company Abstergo Industries, to train their Animus recruits, under the title of the Gladiator.

Source

 * Assassin's Creed: Revelations