Assassin's Creed Unity begins in 1789, the opening year of the French Revolution.
The game places Arno Dorian in Paris as political unrest grows into revolution. Its early historical setting includes the Estates-General, the storming of the Bastille, and the collapse of the old political order. These events provide the background for Arno's personal story and the conflict between the Assassins and Templars.
The date is important because the French Revolution was not a single event confined to one day. It developed through years of upheaval, war, political violence, and changing governments. Unity uses this broad period rather than depicting only the Bastille's fall.
Arno's story continues through later revolutionary milestones, including the Reign of Terror. The game was released in 2014 and is set primarily in Paris, with Versailles also appearing in the campaign.