Beirut was conquered by the Muslims in 635. Prince Arslan bin al-Mundhir founded the Principality of Sin el Fil in Beirut in 759. From this principality developed the later Principality of Mount Lebanon, which was the basis for the establishment of Greater Lebanon, today's Lebanon. As a trading centre of the eastern Mediterranean, Beirut was overshadowed by Acre (in modern-day Israel) during the Middle Ages. From 1110 to 1291, the town and Lordship of Beirut was part of the Kingdom of Jerusalem. The city was taken by Saladin in 1187 and recaptured in 1197 by Henry I of Brabant as part of the German Crusade of 1197. John of Ibelin, known as the Old Lord of Beirut, was granted the lordship of the city in 1204. He rebuilt the city after its destruction by the Ayyubids and also built the House of Ibelin palace in Beirut.