Arguably the most significant ruler Europe has seen, King Canute (anglosized) is definitely one of my favourites. Born circa 995 at Denmark, Canute was the son of Sweyn I (Forkbeard) and Gunhilda. He ascended to the English throne on November 30th, 1016 and crowned at Old St Paul's Cathedral in January 1017, aged 22. He died at Shaftesbury on November 12th, 1035 and was buried at Winchester. Canute reigned for 18 years, 11 months and 11 days.
Interestingly, he married Emma of Normandy, sister to Richard II, who was the royal widow of the hap-hazardous King of the English, Aethelred II (Aethelred and Unready). Little is known of Emma, but together, they produced Edward the Confessor, Aelfred Aetheling and Goda of England.
Canute was King of England from 1016, Denmark from 1018, and Norway from 1028. Having invaded England in 1013 with his father, Sweyn, King of Denmark, he was acclaimed king on Sweyn's death, in 1014, by his Viking army. Canute defeated Edmund (II) Ironside at the Battle of Ashingdon, Essex, in 1016, and became king of all England on Edmund's death. (Canute and Edmund Ironside had divided England up, where Canute ruled Mercia and Northumbria until he inherited the whole kingdom). He succeeded his brother Harold as King of Denmark in 1018, compelled King Malcolm to pay homage by invading Scotland in about 1027, and conquered Norway in 1028. He was succeeded by his illegitimate son Harold I.
Under Canute's rule English trade improved, and he gained favour with his English subjects by sending soldiers back to Denmark. The legend of Canute disenchanting his flattering courtiers by showing that the sea would not retreat at his command was first told by Henry of Huntingdon, in 1130.
The empire collapsed on his death. He was buried at Winchester.