What made Spain richer and stronger throughout the 1500's?

Spain was really the first global superpower, although it might share that limelight with Portugal. Spain (and Portugal) were the first states to be able to truly project their power around the globe, and extend economic relations (i. e., trade) globally as well. After Ferdinand and Isabella united the Castille-Leon and Aragon crowns in 1492 to form the Spanish kingdom, the Habsburgs took over the Spanish imperial throne in the early 1500s, at a time when the Habsburgs ruled the Holy Roman Empire (i. e., most of Germany, Austria, eastern France, Netherlands, Switzerland, northern Italy, Bohemia, "Royal" Hungary, as well as southern Italy (Sicily and Naples). The Habsburg-Spanish imperial empire was at its height under Charles V and his son, Philip II in the 1500s, when Spanish troops were on the Rhine River, in South America, in the Philippines (named after Philip II), in Albania, and elsewhere. Under Philip II the Habsburg empire was split in two, with a Central European (Austria-based) half, and a Western European (Spanish) half. Unfortunately the Spanish wasted much of the vast amounts of money (in the form of silver) pouring into the Spanish treasury from Peru, mostly in fruitless wars trying to suppress Protestantism in Central and northern Europe, and by 1600 Dutch, French and English ships were intruding on Spanish imperial interests and establishing their own colonies. But for most of the 1500s, Spain was easily the world's premier military power.