CHRISTIAN III. was succeeded by his oldest son, Frederick II., who was then twenty-five years old. This vain and worthless monarch commenced his reign with a successful war on the liberty-loving Ditmarshers. Later he waged war on the Swedish king, Erik XIV. The causes of this disastrous war, the so-called Northern Seven Years’ War (1563-1570), were apparently trivial. Both kings wanted to carry the three crowns in their coats-of-arms, and some Swedish messengers, who were on their way to Germany, had been arrested in Denmark; but the real reasons were the jealousy between the two kings and the desire of the Danes to again unite the three countries under a Danish king. At sea the Danes were unsuccessful, although they had very able admirals in Herluf Trolle and Otto Rud. On land they fared no better in the beginning; but, in 1565, the hero, Daniel Rantzau, won a great victory over a much larger army than his own in the battle of Svarteraa in Halland.

Norway, whose defences had been sadly neglected, suffered greatly, during this war, from Swedish incursions. A Swedish army of 4,000 men, under the command of the Frenchman, Claude Collart, conquered Jemteland and Herjedalen and crossed the mountains to Throndhjem. The fortress Stenviksholm was forced to surrender, and the people of Throndhjem and the surrounding districts submitted without resistance and paid homage to the Swedish king. Later, however, Claude Collart was defeated by a fleet sent against him by the governor at Bergenhus, the rich and highly-esteemed Erik Rosenkrands. Claude Collart took refuge in the fortress Stenviksholm; but here he was besieged, and was finally obliged to surrender. He was sent in irons to Copenhagen. Especially hard for the Norwegians was the year 1567, when the Swedes harried Hedemarken, Romerike and Soloer, and captured Hamar. The cathedral of Hamar was burned, and the Swedes marched against Akershus, which was bravely defended by the commander, Kristen Munk. The citizens of Oslo burned their town in order to prevent the Swedes from obtaining a foothold there. On this occasion the Swedes lay encamped on the mountain side above the town, on a plain afterward called the “Swedish plain.” The Norwegians were hard pressed; but Erik Rosenkrands again sent assistance from Bergen, and the Swedes were obliged to leave the country with considerable loss. The incursions of the Swedes were, however, repeated from time to time, and, during one of them, the town of Sarpsborg was burned, January, 1570. Finally, in December, 1570, peace was concluded at Stettin, and the terms were, on the whole, favorable to Denmark. In return for relinquishing her claims to Sweden, which could never have been established, she secured an acknowledgment of her rights to Norway, Scania, Halland and Blekinge, while Sweden returned the Norwegian provinces of Herjedalen and Jemteland, and paid 150,000 Rigsdalers for war expenses. Both countries retained the right to carry the “three crowns” in their coats-of-arms.

The Seven Years’ War was not the only cause of suffering in Norway during the reign of Frederick II. From 1572 Norway was given its own Statholder or viceroy, always a Danish nobleman, who was to reside at Akershus, the fortress near Oslo. But the viceroy did not not have the power, if indeed he desired it, to prevent the prefects and other officers from subjecting the people to cruelties and extortions. They arbitrarily levied taxes, conducted illegal trading, and treated the peasants in a shameful manner. For ten years Erik Munk continued his violent rule in Nedenes. At last, on complaint of the people, he was sentenced to return illegal taxes and indemnify a peasant, whose property he had taken. Later he was deprived of his office and placed in a prison, where he committed suicide. Ludvig Munk, prefect in Throndhjem, even became viceroy, although his conduct as prefect had been such as to cause a conspiracy, which cost the instigators their lives.

The city of Fredericksstad, which was built to replace the ancient Sarpsborg, was named after King Frederick.

During his reign of twenty-nine years, Frederick II. was only once in Norway on a short visit, and knew little of the distress of the country. He amused himself at the palace of Copenhagen, where he led a dissolute life, shortened by drink. He died, April 4, 1588, at the age of fifty-four years.