In Assassin's Creed, Desmond Miles is the modern-day protagonist who relives ancestral memories.
Desmond is taken by Abstergo Industries and connected to the Animus, allowing him to experience the memories of ancestors such as Altaïr Ibn-La'Ahad, Ezio Auditore, and Ratonhnhaké:ton. His modern-day storyline links several historical campaigns and reveals the continuing conflict between the Assassins and Templars.
William Miles is Desmond's father and a senior Assassin, so the two names are sometimes mixed up. Clay Kaczmarek, also known as Subject 16, is another important Animus subject, while Daniel Cross is associated with the Templar side. Desmond remains the central modern-day viewpoint character across the early mainline games, even though later entries use different modern protagonists and narrative formats.