Ethelred the Pious
Sweyn Forkbeard was and remains a powerful symbol of Scandinavia's transitional era at the turn of the Eleventh Century. Besides being King of Denmark, he became the unifier and first King of England, building upon its Saxon and Jórvikish foundations to create the medieval English state.
Sweyn was born in 960, the son of Harald Bluetooth, King of Denmark, and his Queen, Gunhild. Though a baptized Christian, Sweyn saw faith as a very fluid thing. He did not allow his newfound salvation to temper either his ruthlessness or his practice of the religion of his ancestors. He would readily turn to both Odin and Jesus when it suited his purpose. He could behave as a pagan among pagans and a Christian among Christians. He was an ally of the religious leaders of both faiths in his realms in Denmark, England, and Ireland.
Invasion of England
Sweyn became King in 986 after his father's death. Thanks to his father's conquests in the Bloodaxe War, Sweyn's realm included the Kingdom of Østangeln in England, ruled by King Erik of Dyflin as a vassalage. It also included the Jarldom of Orkney and the Isles to the north of Britain.
After securing his position as king with the usual round of wars and assassinations, Sweyn embarked on a campaign to expand his empire in 994. He sailed to his land in Østangeln with a large fleet. With the ships, he began attacking the eastern coasts of the kingdom of Jórvik.
In 995, Sweyn marched an army into the English Midlands. There were victories and setbacks, but word of Sweyn's ruthlessness spread throughout the country. When he campaigned in the south of England the following year, most of the Scandinavian nobility joined his side willingly. But the South was still a largely Anglo-Saxon region in which shire officials competed for influence with the Nordic feudal lords. Some of the villages sought to resist Sweyn and were virtually destroyed.
In 997, Sweyn's advance took him up along Jorvik's northeastern coast. Erik of Dyflin saw that Sweyn's conquest of the kingdom could spell the end of his own independence. He joined with Hrolf of Jorvik to fight against his erstwhile overlord. In 998, Sweyn defeated Hrolf and Erik and captured the city of Jórvik.
King of England
Now a conqueror, Sweyn held court at the city, summoning all the jarls, shire-reeves, lawspeakers, high priests, and bishops of both Jorvik and Ostangeln. They universally elected him King in the traditional Scandinavian fashion. Thenceforth, England was governed as one kingdom with its capital at York.
Sweyn remained in England four more years, shoring up his gains and forging political alliances. In 999 he sailed in the Irish Sea to secure his western coasts. He also traveled to Dyflin to be crowned King of that city. He betrothed his son Cnut to Ingigerd, the daughter of his vanquished foe Hrolf - thus uniting the House of Gorm to the English Ragnarætten.
In 1000 Sweyn and his army secured the Welsh marches. In 1001 he journeyed to Alba to make a pact of friendship with the Scots. The Scots were delighted to have a Christian ruling to the south, but they were understandably nervous about the consolidation of England as a single power. For a hundred years the two English kingdoms had fought one another and largely left Alba alone.
Sweyn returned to Denmark in 1002. He had been in England for eight years. He was distressed but hardly surprised to find his kingdom in the hands of the Swedes. He summoned the Danish nobles and swiftly re-conquered the country.
Sweyn died in 1018. Cnut ascended to the throne of a great Danish Empire: he was King of Denmark, England, and Dyflin and Lord of Orkney and the Isles.