The death of Wenzel in 1419 added a new element of bitterness to the quarrel between the Hussites and the [Sidenote: Crusades against the Hussites.] champions of orthodoxy. The obvious heir to the crown was Sigismund, the only surviving male of the Luxemburg house. But Sigismund was regarded as peculiarly responsible for Hus’s death, and as the representative of all that was foreign and anti-Bohemian. It was inevitable that his claim should be resisted, or only accepted on very stringent conditions. At the moment Sigismund was engaged in a Turkish war, and left the government in the hands of Wenzel’s widow. But as soon as possible he patched up a truce with the Turks, and prepared to take possession of his new kingdom. Frederick of Brandenburg urged him to adopt a conciliatory policy, to play off one party against the other, and to gain over the moderates by a few concessions in religious matters. But Sigismund was eager to secure the support of the Pope, who was resolutely opposed to any tampering with heresy; and most of his German advisers urged that any concessions to his subjects would make them haughty and disobedient in the future. The counsel of Frederick of Brandenburg was rejected, and in March 1420 Martin V. published a crusade against the Hussites. A German army was to be raised to prosecute the religious war. No decision could have been more disastrous. Party divisions in Bohemia were at once reconciled, and all classes joined in maintaining a national resistance against a common foe. And this resistance [Sidenote: Bohemian victories, 1420-22.] was completely successful. Ziska proved to be a general of the first rank. Not only did he give to his troops the cohesion and discipline of a standing army, but he introduced innovations which mark an epoch in the history of mediæval warfare. Especially prominent is the excellence of his artillery, and the use which he made of his baggage-waggons. These were formed into a sort of movable fortress, equally formidable both for defence and aggression. The German armies opposed to him were the feudal levies, collected from various states, bound together by no common interests or enthusiasms, and recognising no common discipline or authority. In three successive campaigns—1420, 1421, and 1422—the Germans were routed and driven from Bohemia, until at last the mere rumour of Ziska’s approach was sufficient to drive his enemies into disorderly and panic-stricken flight. A contemporary says that the Germans were inspired with such a loathing for heretics that they could not bring themselves to strike them, or even to look them in the face.