Olaf, the only son of King Haakon Magnusson and the Danish Margaret, was, at the death of his maternal grandfather, Valdemar Atterdag (1376), proclaimed king of Denmark under the guardianship of his parents, and at the death of his father four years later, when he was ten years old, he inherited the throne of Norway. His mother proceeded to Oslo, where a meeting of the Norwegian chiefs was held early in January, 1381. Here it was arranged that Queen Margaret was to be the guardian of her son and conduct the government in his name, when she was in the country, but in her absence the administration should be conducted by the chieftain Ogmund Finnson, as leader of the state council. Olaf was crowned in Nidaros on Saint Olaf's Day, July 29, 1381. Thus commenced the union between Norway and Denmark, which lasted for over four hundred years and proved so unfortunate for Norway. To the great sorrow of the Norwegians, King Olaf, when scarcely seventeen years old, was taken suddenly sick at Falsterbro Castle, Scania, and died August 3, 1387. Fifteen years after Olaf's death an adventurer appeared who claimed to be King Olaf, and the rumor soon spread that Olaf had escaped from his mother shortly before the time of his alleged death. It was proven, however, that the pretender was a German, and that some merchants, who had noticed the great likeness he bore to Olaf, had induced him to make the claim. The impostor was condemned to death and burned. CHAPTER XXXVII _Margaret (1387-1389)--Erik of Pomerania (1389-1442)--The Kalmar Union (1397)_ As young Olaf left no offspring, it was quite generally supposed in Norway that the kingdom would be given to his nearest relative, Haakon Jonson, a grandson of King Haakon V.'s illegitimate daughter Agneta; but the wily Queen Margaret (who had already been acknowledged as reigning queen of Denmark), induced Archbishop Vinald and the majority of the clergy to take her part, and, at the state council in Oslo, February 2, 1388, she was, as Haakon's widow and Olaf's mother, declared to be the rightful ruler of Norway and its dependencies. According to law, however, the Norwegians were to be ruled by a king, and could not long be satisfied with having the government conducted in the name of a woman. She therefore induced the council to choose her grandnephew, Erik of Pomerania, as king of Norway (1389), she to continue the regency during his minority.