Charles II of Spain was the last Habsburg ruler of the Spanish Empire, reigning from 1665 until his death in 1700. Born in 1661, he faced numerous health issues, which were attributed to the extensive inbreeding within the Habsburg family. His reign was marked by political instability and economic decline, as well as conflicts such as the War of the Spanish Succession. Charles II's inability to produce an heir led to a succession crisis after his death. This situation prompted a struggle for power among European nations, ultimately resulting in the Treaty of Utrecht in 1713, which reshaped the political landscape of Europe.