<P> When, in spite of this, the Norwegian king Olaf Haraldsson and Anund Jakob took advantage of Cnut's commitment to England and began to launch attacks against Denmark, Ulf gave the Danish freemen cause to accept Harthacnut, still a child, as king . This was a ruse on Ulf's part since his role as caretaker of Harthacnut gave him the reign of the kingdom . Upon news of these events, Cnut set sail for Denmark to restore himself and to deal with Ulf, who then got back in line . In a battle known as the Battle of the Helgeå, Cnut and his men fought the Norwegians and Swedes at the mouth of the river Helgea, probably in 1026, and the apparent victory left Cnut as the dominant leader in Scandinavia . Ulf the usurper's realignment and participation in the battle did not, in the end, earn him Cnut's forgiveness . Some sources state that the brothers - in - law were playing chess at a banquet in Roskilde when an argument arose between them, and the next day, Christmas 1026, one of Cnut's housecarls killed the jarl with his blessing, in Trinity Church, the predecessor to Roskilde Cathedral . </P> <P> His enemies in Scandinavia subdued, and apparently at his leisure, Cnut was able to accept an invitation to witness the accession of the Holy Roman Emperor Conrad II . He left his affairs in the north and went from Denmark to the coronation at Easter 1027 in Rome--a pilgrimage to the heart of Christendom being of considerable prestige for rulers of Europe in the Middle Ages . On the return journey he wrote his letter of 1027, like his letter of 1019, informing his subjects in England of his intentions from abroad and proclaiming himself "king of all England and Denmark and the Norwegians and of some of the Swedes". </P> <P> Consistent with his role as a Christian king, Cnut says he went to Rome to repent for his sins, to pray for redemption and the security of his subjects, and to negotiate with the Pope for a reduction in the costs of the pallium for English archbishops, and for a resolution to the competition between the archdioceses of Canterbury and Hamburg - Bremen for superiority over the Danish dioceses . He also sought to improve the conditions for pilgrims, as well as merchants, on the road to Rome . In his own words: </P> <P>... I spoke with the Emperor himself and the Lord Pope and the princes there about the needs of all people of my entire realm, both English and Danes, that a juster law and securer peace might be granted to them on the road to Rome and that they should not be straitened by so many barriers along the road, and harassed by unjust tolls; and the Emperor agreed and likewise King Robert who governs most of these same toll gates . And all the magnates confirmed by edict that my people, both merchants, and the others who travel to make their devotions, might go to Rome and return without being afflicted by barriers and toll collectors, in firm peace and secure in a just law . </P>

Who was the first viking king of england