Plundering expeditions were now made by the Turks into Hungarian territory, but before Sigismund could undertake military operations on his side his death occurred. (December 9, 1437.) The work of defense was then undertaken by his successor and son-in-law, Albert. For the first time the Sultan in person led an army in the region of the Carpathians and the Danube, and, although a coalition was formed, consisting of Hungarians, Servians, and Wallachians, the Turkish arms proved, as so often, irresistible. Semendria was taken, and many thousands of prisoners were carried away from the ravaged countries. But Belgrade held out, though Albert died there among his troops on October 27, 1438. Strong hands were found ready to take up the work of defense. In the city, which was amply protected by a threefold wall, and by many pieces of artillery mounted on the ramparts, there was a garrison of German mercenaries, while in other regions exposed to the invaders, there were Hungarian forces under the command of Johann Hunyadi, the son of a Roumanian peasant of Inidora, whose reputation as a national hero was soon to be made in the victorious leadership of his people against the Turk. Hunyadi’s first aggressive act was an invasion into Bosnia, where he drove out some marauding bands of the Turkish general Isa-beg. A much more important military exploit was the battle of Szt-Imre, where, in 1442 (March 18), the Turks were forced back into Wallachia. Attempts made somewhat later to avenge this humiliation had no final success, for Hunyadi attacked the invading army on its march, winning a victory conspicuous because many well-known Ottoman generals lost their lives. Spurred by the prowess of Hunyadi, the Western powers prepared to support him in driving the Ottomans from Europe. There was additional ground for hope in the arrangements, lately made, for a union between the Eastern and Western churches, a scheme naturally regarded as a good basis for coöperation against the Moslems. A new crusade was proclaimed, but nothing was accomplished by it, since the Venetians feared the loss of their possessions in the East, if the Slavic races were too actively aided, and since the Pope had no inclination to part with the tithes collected for the crusade, while he had use for them in protecting his temporal sovereignty as an Italian prince.