The modern protagonist introduced in the first Assassin's Creed game is Desmond Miles.
Desmond is a former Assassin who has hidden from the Brotherhood before being taken by Abstergo Industries. Scientists use the Animus to access his genetic memories, especially those of his ancestor Altaïr Ibn-La'Ahad. His modern-day storyline connects several early games in the series.
Desmond's family has a long connection to the Assassin Brotherhood. His father is William Miles, a senior Assassin leader. Through the Animus, Desmond later experiences the memories of Ezio Auditore and Connor Kenway, giving the player access to different historical periods.
Players sometimes confuse Desmond with William because both are important modern Assassins. William is Desmond's father, while Desmond is the playable modern viewpoint character in the early main entries. Layla Hassan becomes the central modern protagonist much later, beginning with Assassin's Creed Origins.