Throughout its history, it served as a base of operations for the Templar Order, with the renovation of the shipyard in 1320 being paid for by Templar funds. As such, the facility was treated by the Assassins as a Templar lair.
First built as a naval depot for private ships, the Arsenal was rebuilt and enlarged in 1320. From that point on, it was used by the Venetian state to construct and maintain its ships.
Famously, at the peak of production, shipbuilders at the Arsenal were able to produce an entire ship in a day. The impressive front gate (the Porta Magna) went up in 1460, in the classical Revivalist style.
Whilst in Venice, the Assassin Ezio Auditore infiltrated the Arsenale drydocks. Entering through a small building in the vicinity, Ezio engaged in a chase with an Agile guard through the docks, and by the time he had caught and killed the guard, the pursuit had brought him to a room containing a Templar strongbox. After taking what he wanted of its contents, Ezio exited through a small tunnel, returning to the streets of Venice.
In 1486, the Arsenal served as the point of departure for the Templar vessel destined to collect an Apple of Eden from Cyprus, and also as the point of arrival for the aforementioned vessel two years later.