Harthacnut of Denmark

Harthacnut
Penny struck in Harthacnut's name
King of Denmark
Reign	1035 – 8 June 1042
Predecessor	Cnut the Great
Successor	Magnus I
King of England
Reign	17 March 1040 – 8 June 1042
Coronation	June 1040 (Canterbury)
Predecessor	Harold Harefoot
Successor	Edward the Confessor
Born	c. 1018 England
Died	8 June 1042 (aged 23–24) Lambeth, England
Burial	Winchester Cathedral, England
House	House of Denmark
Father	Cnut, King of Denmark and England
Mother	Emma of Normandy
Religion	Catholicism (pre-reformation)

Harthacnut (Danish: Hardeknud; "Tough-knot"; c.1018 – 8 June 1042), sometimes referred to as Canute III, was King of Denmark from 1035 to 1042 and King of England from 1040 to 1042.

He was the son of King Cnut the Great (who ruled Denmark, Norway, and England) and Emma of Normandy. When Cnut died in 1035, Harthacnut struggled to retain his father's possessions. Magnus I took control of Norway, but Harthacnut succeeded as King of Denmark and became King of England in 1040 after the death of his half-brother Harold Harefoot.

Harthacnut died suddenly in 1042 and was succeeded by Magnus in Denmark and Edward the Confessor in England. Harthacnut was the last Scandinavian to rule England.

Harthacnut was born shortly after the marriage of his parents in July or August 1017. Cnut had put aside his first wife Ælfgifu of Northampton to marry Emma, and according to the Encomium Emmae Reginae, a book she inspired many years later, Cnut agreed that any sons of their marriage should take precedence over the sons of his first marriage. In 1023, Emma and Harthacnut played a leading role in the translation of the body of the martyr St Æelfheah from London to Canterbury, an occasion seen by Harthacnut's biographer, Ian Howard, as recognition of his position as Cnut's heir in England.

In the 1020s, Denmark was threatened by Norway and Sweden, and in 1026, Cnut decided to strengthen its defences by bringing over his eight-year-old son to be the future king under a council headed by his brother-in-law, Earl Ulf. However, Ulf alienated Cnut by getting the Danish provinces to acknowledge Harthacnut as king without reference to Cnut's overall authority and by failing to take vigorous measures to meet Norwegian and Swedish invasions, instead waiting for Cnut's assistance. In 1027, Cnut arrived with a fleet. He forgave Harthacnut his insubordination in view of his youth but had Ulf murdered. He drove the invaders out of Denmark and established his authority over Norway, returning to England in 1028 and leaving Denmark to be ruled by King Harthacnut.