Frederik III was the King of Denmark from 1648 until his death in 1670. He was born on March 18, 1609, and was the son of Christian IV and Anne Catherine of Brandenburg. His reign is noted for the establishment of absolute monarchy in Denmark, which centralized power in the hands of the king. During Frederik III's rule, Denmark faced several challenges, including wars with Sweden and economic difficulties. He is also known for his efforts to strengthen the Danish navy and improve the country's infrastructure. His legacy includes the promotion of trade and the arts, contributing to Denmark's development during the 17th century.