Magnus, son of Harold Godwinson

Magnus's precise date of birth is unknown, but can be estimated from the fact that his elder brother is thought to have been born in the mid- or late 1040s.^[1][2] His family was one of the most powerful in Anglo-Saxon England: his paternal grandfather was Godwin, Earl of Wessex, and his father was Harold Godwinson, who at about this time inherited the same title. His mother, Edith Swan-neck, was married to Harold more danico, "in the Danish manner", that is to say they had a form of marriage which was not recognized by the Church but which was at the time widely considered legitimate among the laity. Harold Harefoot, for example, succeeded to the throne despite being the son of such a marriage between king Cnut and Ælfgifu of Northampton.^[3] Harold Godwinson had five sons, probably not by the same mother, and Magnus seems to have been either the second or third of these.^[4][5] Magnus was almost certainly named after Magnus the Good, king of Norway, who was himself the first to bear that Christian name.^[6] Magnus Haroldson can be presumed to have received an education befitting the son of a great nobleman, with the emphasis on gaining military and diplomatic skills, and though he was apparently too young to fight for his father, now king of England, at the Battle of Hastings, he had opportunities to use these skills in the next few years.^[7]

Harold Godwinson's defeat and death at Hastings were a disaster for his family, especially since the English magnates in London responded by electing as king not one of Harold's sons but Edgar Ætheling, a great-nephew of Edward the Confessor. Edgar's brief "reign" – he was never actually crowned – ended when William the Conqueror reached London in December 1066.^[8] Magnus's grandmother Gytha, the widow of Earl Godwin, retreated to the south-west of England to consolidate her power in that still unconquered part of the country, but at the beginning of 1068 William led his army against her, and besieged her in Exeter.^[9] Magnus is not specifically mentioned in contemporary sources as being part of this south-western rebellion, but it is very likely that he and his brothers Godwin and Edmund were there, asserting their claim to be leaders of the English opposition.^{[10][11][12][13]} After eighteen days Exeter submitted to William, but by that time Gytha, and perhaps her grandchildren, had escaped and taken refuge on an island in the Bristol Channel, probably Steep Holm.^[2][14][15]

That summer Magnus's brother Godwin was in Dublin under the protection of king Diarmait of Leinster, who had many years previously given refuge similarly to his father. Godwin was accompanied by Edmund and Magnus, if we are to believe the chronicler John of Worcester, or by Edmund and his first cousin Tostig (a son of Swein Godwinson) if we believe the Anglo-Norman chronicler Geoffrey Gaimar. They seem to have had Harold Godwinson's remaining housecarls in their service, and still had the resources to make Diarmait gifts such as the "battle standard of the king of the Saxons" mentioned by the Annals of Inisfallen, and to hire a force of mercenaries.^[16][17] With a fleet of 52 ships they sailed to the Bristol Channel and first harried the area around the mouth of the river Avon, then attacked Bristol, and after being driven off by the townspeople they sailed back to the Somerset coast and landed again.^[18][19][20] They may have expected a welcome there and planned to recruit more men, since Godwin's only landholdings at the death of Edward the Confessor had been two small manors in Somerset at Nettlecombe and Langford-in-Burrington, but if so they were disappointed.^[21][22] They encountered a local force under the command of Eadnoth the Staller which fought a bloody battle with them at Bleadon. Eadnoth was one of the fatalities, and possibly also Magnus. After harrying Devon and Cornwall the surviving brothers returned to Dublin, richer but having won no great military success.^[20] It is, to sum up, uncertain if Magnus took part in this raid, and if he did take part it is uncertain whether he survived it.

There is no further explicit mention of Magnus by any contemporary source, but it is recorded that two unnamed sons of Harold made a second raid on south-west England in the summer of 1069 which ended with the disastrous Battle of Northam fought in Devon against the forces of Brian of Brittany, resulting in the deaths of "all the best men" of the brothers' expedition.^[23][24][20]