During the late 15th and early 16th centuries, Ferdinand and Isabella unified Spain and expanded its territories through conquests. Their funding of Columbus's expedition led to the discovery of America, beginning the Spanish Empire. Charles I expanded the empire further, though faced problems from revolts. Philip II made the empire even larger but costly wars impoverished Spain. The Spanish Golden Age between 1560-1680 was a high period for arts and culture. By the 17th century, weak rulers and revolts diminished Spain's power, leading to a succession dispute and war in the early 18th century.