Less serious than the struggle with Henry the Lion was Frederick's struggle with Philip of Heinsberg, archbishop of Cologne (d. 1191), on whom he had just conferred a great part of Saxony. When the emperor went to Italy in 1184 he left the government of Germany to his son Henry, afterwards the emperor Henry VI., who had been crowned German king in 1169. On all sides, but especially in the north-west, Henry was faced with incipient revolution, and while he was combating this the quarrel between Frederick and the Papacy broke out again in Italy. At this juncture Philip of Cologne united the German and the Italian oppositions. Several princes rallied to his standard and foreign powers promised aid, but although very formidable in appearance the combination had no vestige of popular support. The greater part of the German clergy again proved their loyalty to Frederick, who hurried to Germany only to see the opposition vanish before him. In March 1188 Philip of Cologne submitted at Mainz. Frederick's death. Germany was now at peace. With the accession of Gregory VIII. pope and emperor were reconciled, and by the marriage of his son Henry with Constance, daughter of Roger I., king of Sicily, the emperor had reason to hope that the Empire would soon include Naples and Sicily. Resolving that the sunset of his life should be even more splendid than its dawn he decided to go on crusade, and in 1189 he started with a great army for the Holy Land. When the news reached Germany that he had been drowned, an event which took place in Cilicia in June 1190, men felt that evil days were coming upon the country, for the elements of discord would no longer be controlled by the strong hand of the great emperor. Henry VI.