The remainder of Haakon's reign was externally uneventful, and for that very reason beneficial to the country. The king was wise enough to see that the noisy deeds of war bring no enduring blessing, while the industries of peace produce sound prosperity and progress. He therefore devoted himself with unflagging energy to the furtherance of agriculture and trade. His chief interest was, however, architecture. Cloisters, churches, and fortifications were built in different parts of the country. His love of splendor he indulged in the erection of a magnificent royal mansion in Bergen, and his benevolence in the erection of a hospital for lepers. In Tromsö he put up a church, which long enjoyed the distinction of being the northernmost church in the world. The laws of succession were so amended as to exclude illegitimate sons; the civil and criminal codes were improved, and the number of lawmen increased to eleven. A well-equipped fleet of 300 ships was maintained, which, in the hands of a peace-loving king, was a guaranty of peace rather than a menace of war. By embassies, by exchanges of gifts with foreign princes, and by the power and splendor which he displayed at home and abroad, Haakon gained a place among the rulers of Europe, which had been accorded to no Norwegian king before him. The German emperor, the noble and gifted Frederick II., sought his friendship, and maintained communication with him until his death. The Russian grand duke, Alexander Newsky, applied for the hand of his daughter, Christina, for his son, and King Alfonso the Wise of Castile wooed her for his brother. The suit of the latter was accepted, and Christina married in 1257 the Spanish prince, Don Philip. The Pope, Alexander IV., endeavored to extort from Haakon a promise to participate in a crusade, and the king of France, Louis IX., offered him, "in view of his power and experience on the seas," the command of an allied Norse-French fleet; and to crown his honors, it is said that the Pope in 1256 urged him as his candidate for emperor of Germany.