What is the name of Desmond Miles's father in the Assassin's Creed series?

Desmond Miles's father in the Assassin's Creed series is William Miles.

William is a senior member of the modern Assassin Brotherhood and serves as an important mentor and organizer during the modern-day storyline. He belongs to the Miles family, which has a long connection to the Assassin cause. His relationship with Desmond is strained at first, partly because William raised him within the Brotherhood's secretive world.

William becomes more directly involved after Desmond joins the modern Assassin team. He works with Rebecca Crane, Shaun Hastings, and other allies while they use the Animus to investigate ancestral memories and search for ways to oppose Abstergo Industries.

Players can confuse William with Warren Vidic, the Abstergo scientist who supervises Desmond's early Animus sessions, or with Desmond's ancestor Altaïr. William is a modern-day character and Desmond's father, not an ancestor experienced through the Animus.