The Crusaders main fortress (castrum) and headquarters, halls and structures are located on the North-West side of the city. Excavations in recent years reconstructed many of the large structures which are located under and south to the Ottoman/British citadel. In this place was the Crusaders’ Royal palace and main headquarters after retreating from Jerusalem.
These halls were built by the “Hospitallers” – the order of the Knights of the Hospital of Saint John – in the beginning of the 12th C, after the Crusaders captured the city in 1104.
The Crusaders were driven out from Jerusalem by Saladin in 1187, and Acre also fell to Saladin’s forces. However, several years later Richard the Lion Heart headed a new Crusade and retook the city (1191), and established the capital of the remnant of the Kingdom of Jerusalem. This was the Crusaders last stronghold in the Holy Land. They enforced and expanded their central fortress and palace on the site and ruled their smaller Kingdom from the Citadel. The city’s port enabled them to keep the vital supply line to Europe.
This lasted 100 years: In 1291 the city was taken by the Mamlukes, and was completely destroyed.