Canute IV became King of Denmark upon the death of his brother Harald III.

Canute IV, later known as Canute the Holy or Saint Canute, was King of Denmark from 1080 until 1086. Canute was an ambitious king who sought to strengthen the Danish monarchy, devotedly supported the Roman Catholic Church, and had designs on the English throne. Slain by rebels in 1086, he was the first Danish king to be canonized. He was recognized by the Roman Catholic Church as patron saint of Denmark in 1101.

This is a list of monarchs of Denmark, that is, the kings and queen regnants of Denmark. This includes:

• The Kingdom of Denmark
  • Personal union of Denmark and Norway (1380–1397)
• The Kalmar Union (1397–1536)
  • Union of Denmark, Norway and Sweden (1397–1523)
  • Union of Denmark and Norway (1523–1536/1537)
• The United Kingdoms of Denmark–Norway (1536/1537–1814)
• The Kingdom of Denmark (1814–present)
  • Iceland
  • Greenland
  • Faroe Islands

Harald Hen was King of Denmark from 1076 to 1080. Harald III was an illegitimate son of Danish king Sweyn II Estridsson, and contested the crown with some of his brothers. He was a peaceful ruler who initiated a number of reforms. Harald was married to his cousin Margareta Hasbjörnsdatter, but did not leave any heirs, and was succeeded by his brother Canute IV the Saint. Four of his half-brothers were in turn crowned Danish kings.