Which Assassin's Creed game introduced the Brotherhood's recruit-and-command system in Renaissance Rome?

Assassin's Creed: Brotherhood introduced the recruit-and-command system in Renaissance Rome.

The game continues Ezio Auditore's story after Assassin's Creed II. Ezio works to rebuild the Assassin Brotherhood in Rome, recruiting citizens and training them so they can assist during missions or be called in during combat.

Brotherhood also centers on the conflict with the Borgia family, especially Cesare Borgia. Controlling districts and restoring shops and landmarks helps Ezio strengthen his position in the city. This gives the game a broader management layer than its predecessor.

Assassin's Creed II introduced Ezio and the Renaissance setting, while Revelations later concluded the main part of his personal story in Constantinople. Brotherhood is the specific title associated with the recruitable Assassin system and its Rome-based campaign.