The founder of the Danish monarchy was Gorm the Old (p. 12); he first united all the land. About 935 he was succeeded by Harald of the Blue Tooth (Blaatand). Him the Holy Roman Emperor was to some extent able to control and insisted on his becoming a Christian. Traditionally at any rate he was the founder of Roskilde Cathedral, erecting a church of staves where before no church had been. Men say, the _Heimskringla_ informs us, that Keisar Otto II. was the gossip of his son, Svein Twibeard. So lightly, however, did Twibeard regard the solemn ceremony of his baptism that, heading the pagan party, he flung his father from the throne and began to reign himself about the year 985. More than once he changed his creed, but it seems that he happened to be trowing in the faith of the White Christ at the time of his unlamented death. He it was who fought against Olaf Tryggvison in the famous Long Worm at Svoldr, but he left when the fighting was of the sharpest and much folk fell. Nevertheless his Norwegian ally, Earl Eric, who had a beaked ship wondrous great, captured the Long Worm itself, when Olaf Tryggvison leapt into the deep sea and was never heard of more. While at war with Ethelred the Redeless in "England it betid there that King Svein, the son of Harald, died suddenly anight in his bed; and it is the say of Englishmen that Edmund the Holy did slay him after the manner in which the holy Mercury slew Julian the Apostate."[50] He is buried according to tradition under the Castle Hills at Gainsborough on the Trent. He had won a firm position on English soil, and notwithstanding the victory of Ethelred the Redeless and St. Olaf at London Bridge, his son, Knut the Rich, the Mighty, the Great--for so he is variously called--eventually established his power both in England and Denmark.