Frederick III (March 18, 1609 – February 9, 1670) was king of Denmark and Norway from 1648 until his death, and instituted Denmark as an absolute monarchy in 1660. He was born as the second-eldest son of Christian IV of Denmark and Anne Catherine of Brandenburg. Frederick was only considered an heir to the throne after the death of his older brother Prince Christian in 1647. At the death of Christian IV, Frederick conceded significant influence to the nobility, in order to be elected king.