The Venetians and Pisans, who also had trading links with Tripoli, were shocked at this and supposedly conspired with the Mameluk sultan Qalawun to attack the city. Lucia allied with the Mongols, who, knowing that Tripoli was too weak to defend itself even with their help, asked for support from Europe, although no aid was to be found there. Qalawun started the Siege of Tripoli for one month in 1289 and captured it on April 26. Two years later Acre, the last Crusader outpost in the Holy Land was also captured.