Which Assassin's Creed game introduced the series' naval ship, the Jackdaw?

Assassin's Creed IV: Black Flag introduced the naval ship Jackdaw to the series.

The Jackdaw is a brig commanded by Edward Kenway, the game's Welsh privateer-turned-Assassin protagonist. Edward acquires the vessel early in the story and uses it to explore the Caribbean, attack rival ships, raid forts, and travel between islands. Ship upgrades are central to progression, making naval combat one of the game's defining systems.

Assassin's Creed III had already introduced important naval missions, especially through Connor Kenway's ship, the Aquila. However, Black Flag expanded that idea into a large, persistent open-world sailing system. The Jackdaw therefore represents the first major player ship built around continuous exploration rather than a limited sequence of missions.

The name Jackdaw refers to a bird in the crow family and suits the game's recurring imagery of piracy and freedom. The ship is also central to Edward's relationships with pirates such as Edward Thatch and Bartholomew Roberts.