Harold I, also known as Harold Harefoot, was regent of England from 1035 to 1037 and King of the English from 1037 to 1040. Harold's nickname "Harefoot" is first recorded as "Harefoh" or "Harefah" in the twelfth century in the history of Ely Abbey, and according to some late medieval chroniclers it meant that he was "fleet of foot".
Harold Harefoot drawn in the 13th century, from The Life of King Edward the Confessor by Matthew Paris
Cnut, king of England, Denmark, and Norway, and his sons Harald Harefoot and Harthacnut
Silver penny of Harold I
The runestone Sm 42, in Småland, Sweden, mentions "Haralds kunungs", probably meaning King Harold Harefoot.
Harthacnut, traditionally Hardicanute, sometimes referred to as Canute III, was King of Denmark from 1035 to 1042 and King of the English from 1040 to 1042.
Harthacnut in the 14th-century Genealogical Roll of the Kings of England
Cnut, king of England, Denmark, and Norway, and his sons Harold Harefoot and Harthacnut
Silver penny of Harthacnut
Harthacnut (left) meeting the young King Magnus the Good at the Göta älv river in modern-day Sweden. Illustration by Halfdan Egedius.