In 1396, Sigismund led the combined armies of Christendom against the Turks, who had taken advantage of the temporary helplessness of Hungary to extend their dominion to the banks of the Danube. This crusade, preached by Pope Boniface IX, was very popular in Hungary. The nobles flocked in their thousands to the royal standard, and were reinforced by volunteers from nearly every part of Europe. The most important contingent being that of the French led by John the Fearless, son of Philip II, Duke of Burgundy. Sigismund set out with 90,000 men and a flotilla of 70 galleys. After capturing Vidin, he camped with his Hungarian armies before the fortress of Nicopolis. Sultan Bayezid I raised the siege of Constantinople and, at the head of 140,000 men, completely defeated the Christian forces in the Battle of Nicopolis fought between the 25 and 28 September 1396. Sigismund returned by sea and through the realm of Zeta, where he ordained a local Montenegrin lord Đurađ II with the islands of Hvar and Korčula for resistance against the Turks; the islands were returned to Sigismund after Đurađ's death in April 1403. No new expedition was launched from Western Europe to stop the Turkish advance in the Balkans after this defeat, until the 1440s.