Moreover, his regulations against heresy were part of his general code of law for the government of the diverse races in his kingdom of Sicily, and in this code issued in 1231, although their temporalities were secured to the clergy, as a class they were subjected to taxation and to the secular jurisdiction of the State. Pope Gregory's counter-blast to this policy is contained in his addition to the Canon Law known as his Decretals (1234). By these the clergy were declared entirely exempt from secular taxation and jurisdiction, on the ground that all secular law was subordinate to the law of the Church, and that the duty of the secular power was to carry out the commands of the Church. [Sidenote: The second contest.] Thus each side was maintaining its pretensions until the opportunity should come for asserting them. This was found for the second time in the affairs of Lombardy. The Lombard cities still feared the designs of Frederick. In 1235 they renewed their League. Again the Pope was accepted as arbiter, and again Frederick complained with justice that he was too favourable to the cities. In 1236 Frederick declared war against the League. His pretext of punishing heresy which was rife in Lombardy, deceived no one; while his declaration, when Gregory desired him to turn his arms to Palestine, that "Italy is my heritage, and this the whole world knows," confirmed the worst apprehensions of the Pope and the Lombards. Moreover, Frederick's first move was entirely successful, and in 1237 he completely defeated the Lombards in battle at Corte Nuova, took the Milanese standard and sent it to be placed in the Capitol at Rome. The subjugation of the Lombards would mean the union of Italy under Frederick's rule, while, since the acquisition of Sicily by the Hohenstanfen, the Lombards remained the only allies of the Papacy in Italy. Gregory therefore declared himself, and in March, 1239, he excommunicated Frederick and released his subjects from their allegiance. Frederick issued a manifesto addressed to all Princes, in which he appealed to a General Council. Gregory's counter-manifesto was couched in terms of the most unrestrained violence. Frederick was described as the beast in the Apocalypse (Rev. xiii. 1), which had upon its seven heads the name of blasphemy; and he is charged with saying that the world had been deceived by three impostors, Christ, Moses and Mohammed, of whom two had died in glory, while the third had been crucified.