section_path: History/Reformation and Renaissance
section_name: Reformation and Renaissance
paragraph_text: Reformation and Renaissance
  
  In 1516, Ferdinand II of Aragon, grandfather of the future Holy Roman Emperor Charles V, died. Charles initiated his reign in Castile and Aragon, a union which evolved into Spain, in conjunction with his mother Joanna of Castile.
  
  In 1519, already reigning as Carlos I in Spain, Charles took up the imperial title as Karl V. The Holy Roman Empire would end up going to a more junior branch of the Habsburgs in the person of Charles's brother Ferdinand, while the senior branch continued to rule in Spain and the Burgundian inheritance in the person of Charles's son, Philip II of Spain. Many factors contribute to this result. For James D. Tracy, it was the polycentric character of the European civilization that made it hard to maintain "a dynasty whose territories bestrode the continent from the Low Countries to Sicily and from Spain to Hungary – not to mention Spain's overseas possessions". Others point out the religious tensions, fiscal problems and obstruction from external forces including France and the Ottomans. On a more personal level, Charles failed to persuade the German princes to support his son Philip, whose "awkward and withdrawn character and lack of German language skills doomed this enterprise to failure".
  
  Before Charles's reign in the Holy Roman Empire began, in 1517, Martin Luther launched what would later be known as the Reformation. The empire then became divided along religious lines, with the north, the east, and many of the major cities – Strasbourg, Frankfurt, and Nuremberg – becoming Protestant while the southern and western regions largely remained Catholic.
  
  At the beginning of Charles's reign, another Reichsregiment was set up again (1522), although Charles declared that he would only tolerate it in his absence and its chairman had to be a representative of his. Charles V was absent in Germany from 1521 to 1530. Similar to the one set up in the early 1500s, the Reichsregiment failed to create a federal authority independent of the emperor, due to the unsteady participation and differences between princes. Charles V defeated the Protestant princes in 1547 in the Schmalkaldic War, but the momentum was lost and the Protestant estates were able to survive politically despite military defeat. In the 1555 Peace of Augsburg, Charles V, through his brother Ferdinand, officially recognized the right of rulers to choose Catholicism or Lutheranism (Zwinglians, Calvinists and radicals were not included). In 1555, Paul IV was elected pope and took the side of France, whereupon an exhausted Charles finally gave up his hopes of a world Christian empire.