Frederick II (1 July 1534 – 4 April 1588) was King of Denmark and Norway and Duke of Schleswig and Holstein from 1559 until his death.
A member of the House of Oldenburg, Frederick began his personal rule of Denmark-Norway at the age of 24. He inherited a capable and strong kingdom, formed in large by his father after the civil war known as the Count's feud, after which Denmark 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. However, after miscalculating the cost of the Northern Seven Years' War, he pursued a more prudent foreign policy. The remainder of Frederick II's reign was a period of tranquillity, in which king and nobles prospered, and were Frederick instead focused more on hunting and feasting with his councillors as well as architecture and science. The period saw a great number of architectural constructions, including the royal castles of Kronborg at Elsinore and Frederikborg Castle at Hillerød.
Frederick has to a great extent been overshadowed by his popular, long-reigning son Christian IV, and often been portrayed with skepticism and resentment, resulting in the prevailing portrait of Frederick as a man and as king: an unlettered, inebriated, brutish sot. This portrayal is, however, inequitable and inaccurate, and recent studies reappraise and acknowledge him as highly intelligent; he craved the company of learned men, and in the correspondence and legislation he dictated to his secretaries he showed himself to be quick-witted and articulate. Frederick was also open and loyal, and had a knack for establishing close personal bonds with fellow princes and with those who served him.
In 1572, Frederick married his cousin Sophie of Mecklenburg. Their relationship is regarded as one of the happiest royal marriages in Renaissance Europe. In the first ten years after the wedding, they had seven children, and are described as inseparable and harmonious.
Frederick was committed to becoming the mightiest king in the North, and for several years he fought exhausting wars against his archrival Erik XIV of Sweden, after which the battles changed character. It became a competition to see who could trace their family history the furthest, and who could construct the most formidable castles. In the 1570s he constructed Kronborg, a large Renaissance castle that became widely recognized abroad, and its dance hall was the largest in Northern Europe at the time. He enjoyed entertaining guests and throwing elaborate festivities, which were well-known throughout Europe. During the same period, the Danish-Norwegian fleet was developed into one of Europe's largest and most modern. As part of his efforts to strengthen the kingdom, he provided much support for science and culture.