Frederick II (Danish: Frederik 2.; 1 July 1534 – 4 April 1588) was King of Denmark and Norway and Duke of Schleswig and Holstein from 1559 until his death in 1588.
A member of the House of Oldenburg, Frederick began his personal rule of Denmark-Norway at the age of 24. He inherited capable and strong realms, formed in large by his father after the civil war known as the Count's Feud, after which Denmark-Norway saw a period of economic recovery and of a great increase in the centralised authority of the Crown.
Frederick was, especially in his youth and unlike his father, belligerent and adversarial, aroused by honor and national pride, and so he began his reign auspiciously with a campaign under the aged Johan Rantzau, which reconquered Dithmarschen.