Earl Haakon waited for an opportunity to repudiate his obligations to the Danish king, and it came in time. In 973, when Otto II. became emperor of Germany, King Harald Bluetooth prepared himself for war in order to resist the emperor's claim to sovereignty over Denmark, and in 975 he ordered Earl Haakon to come to his aid with all the forces it was possible to raise. Haakon complied with the request, and for a time successfully fought the Germans. But when he had boarded his ships and prepared to sail homeward, the emperor returned for a second attack, and soon compelled the Danish king to make peace. King Harald Bluetooth agreed to introduce Christianity both in Denmark and in Norway. He sent for Earl Haakon and made him accept baptism and promise to introduce Christianity in Norway. Priests were sent with him to help him with this work. Haakon set sail with the priests on board; but no sooner did he get a favorable wind than he put the priests ashore, and sailed away. From now on he considered himself the sworn enemy of the Danes. He steered through the Sound, and harried the coasts on both sides. At the coast of East Gautland he made a great heathen sacrifice. Thereupon he burned his ships and marched through the country with his men. He defeated Earl Ottar, the ruler in Gautland, and continued his march through Smaaland and West Gautland to Norway. He again took up his residence in Throndhjem. King Harald Bluetooth was greatly incensed at Earl Haakon's action, and decided to take an awful revenge. He collected a great fleet, which he brought to Norway. He burned and destroyed the settlements and killed a great number of people wherever he came. In Lærdal in Sogn, it is said that only five dwellings were left unburned. The inhabitants fled to the woods with such movable goods as they could save. As soon, however, as it was reported that Earl Haakon was coming southward with a fleet, King Harald lost his courage, set sail, and returned to Denmark.