King Charles XI of Sweden was a monarch who reigned from 1660 to 1697. He was born on November 24, 1655, and became king at the young age of five after his father, King Charles X Gustav, passed away. His reign is noted for significant military and administrative reforms that strengthened the Swedish state. During his rule, Charles XI focused on consolidating power and improving the economy. He implemented a system of absolute monarchy, which allowed him to centralize authority. His efforts laid the groundwork for Sweden's future stability and prosperity, making him a pivotal figure in Swedish history.