During the reign of Philip IV (1621–1665) tensions between Catalan institutions and the Monarchy arouse. In the Courts of 1626 the king tried to pass the proposal of Union of Arms designed by his chief minister Gaspar de Guzmán, Count-Duke of Olivares, demanding a military contribution from every realm of the Spanish Crown, including the Principality of Catalonia. However, the Courts were never concluded, due to the opposition of the estates to the measures of Olivares, many of which were contrary to the Catalan constitutions. Those events, coupled with the increased discomfort among Catalan population led to the Reapers' War (1640–1652).