King Charles XI was the King of Sweden from 1660 until his death in 1697. He became king at a young age after the death of his father, King Charles X Gustav. His reign is noted for significant military and political reforms, which strengthened the Swedish state and economy. During his rule, Charles XI implemented the Great Reduction, a policy that reclaimed land from the nobility to increase royal power. He also focused on improving the military and fostering trade, which helped Sweden maintain its status as a major European power during the late 17th century.