As part of the Italian Wars, France went to war with Aragon over the kingdom in 1502; the war ended in an Aragonese victory that left Ferdinand II in full control of the kingdom by 1504. The Spanish held control of Naples throughout the 17th century where it remained an important source of economic and military power for the Spanish Crown. After the War of the Spanish Succession in the early 18th century, the possession of the kingdom again changed hands; the 1714 Treaty of Rastatt saw Naples given to Charles VI of the Austrian Habsburgs. However, Naples and Sicily were conquered by Charles, Duke of Parma (of the Spanish Bourbons) during the War of the Polish Succession in 1734, he was then installed as King of Naples and Sicily from 1735. In 1816, Naples formally unified with the island of Sicily to form the Kingdom of the Two Sicilies.
