The Auberge de Castille is located within the city of Valletta and houses the office of the Prime Minister of Malta.
The Auberge de Castille was the official seat of the knights of the Langue of Castille, Léon and Portugal – one of the most powerful of the Order, its Head being the Grand Chancellor. The Knights of this Langue were responsible for the defence of part of the fortifications of Valletta, known as the St Barbara Bastion. The Auberge is situated at the highest point of Valletta and originally looked out on the rolling countryside beyond, giving it a unique vantage-point unsurpassed by any other building in the city.
The original Auberge was built by the renowned Maltese architect Girolamo Cassar in 1574. It was extensively re-modelled and virtually rebuilt in 1741, the present plan of the imposing structure attributed to Andrea Belli. The building was damaged during the siege of the French forces (1799–1800) as well as during the Second World War (1939–1945).
Following the departure of the Knights, the Auberge de Castille served as the headquarters of the French occupation forces between 1798 and 1800 and as the British army headquarters after 1800. It became the Office of the Prime Minister in 1972.