Which Assassin's Creed game introduced the franchise's first playable female protagonist?

Assassin's Creed III: Liberation introduced the franchise's first playable female protagonist.

Liberation stars Aveline de Grandpré, a mixed-race woman who becomes an Assassin in eighteenth-century New Orleans. The game was originally released for PlayStation Vita in 2012 alongside Assassin's Creed III, making Aveline the first woman to lead a playable Assassin's Creed game.

Aveline can use different disguises, each changing how guards and civilians react to her. Her story also travels beyond New Orleans to locations including the Louisiana bayou and Chichen Itza. A remastered version was later released for other platforms.

Syndicate includes Evie Frye, but it came later in 2015. Odyssey allows players to choose Kassandra or Alexios, and Unity's main campaign centers on Arno. Those facts do not change Liberation's priority as the first game with a female lead character.