About 1320 the Emperor Andronikos II imposed a further round of taxes on his subjects. The taxgatherers did their work thoroughly. The failing economy of the empire showed signs of reviving. The emperor proposed to spend some of the proceeds on building a fleet of twenty warships and on maintaining a standing army of 1000 cavalry in Bithynia in Asia Minor and 2000 in Thrace and Macedonia. He needed the rest for administration, for embassies and for satisfying his creditors in Venice and other places. His subjects were already overtaxed. They knew that much of what they were asked to pay went into the pockets of the emperor's officials and not into the treasury. This was one of the causes of the general discontent with the government and the policies of Andronikos II. But there were also particular discontents within the ruling family; and it was these that precipitated a war for the possession of the throne. By 1321 Andronikos had reigned for nearly forty years, years during which things seemed to have gone from bad to worse. There were many in high places who felt that the time had come for him to go and to hand over to a younger generation with new ideas. He had planned that his dynasty should be perpetuated through his son Michael IX and his grandson Andronikos III. But Michael died in 1320. It was said that his death had been hastened by the behaviour of his son, the young Andronikos, who had once been his grandfather's favourite.