The Castle is situated on the Island of Sant’Andrea, at the entrance to the city port. Originally this was a military outpost. The construction of a square keep was started in February 1481 by Ferdinand I of Naples. Just a few years later (in 1485), Alfonso II of Naples, Duke of Calabria, converted this initial defensive core into a full-fledged castle. The addition of mighty bulwarks and seawalls extended the fortress towards the North-East. To ensure greater safety, the small fortress was completely shut off with its only opening on the eastern side of a canal. A large room on the first floor and barrel-vaulted corridors on the lower floor were built in 1492, completing the Castle as we know it today. The reddish carparo limestone quarried from the island and used to build the castle earned it the name of the Red Castle.
In 1558 the construction of the Fort was started in order to defend the section of the island that was still unprotected and to avoid enemy attacks, following the attack launched from Venetian ships in 1528.
In 1577, two large bastions were built linking the Fort to the ancient fortress. The old defence canal was thus closed, forming the harbour that exists today.
The Castle is property of State but is presently on loan to the Brindisi Navy.