Magnus II of Norway

He appears to have assisted Welsh ruler Gruffydd ap Llywelyn and Ælfgar, Earl of Mercia in their struggles against Wessex, although his primary objective may have been to assert control over Orkney.

"[3] While not mentioned anywhere in the sagas, Magnus appears in contemporary British sources around the year 1058 as the leader of a Norwegian expedition in the Irish Sea.

[5] The expedition also appears to have supported a branch of the Norse-Gaelic dynasty of Ivar that opposed Irish king Diarmait mac Maíl na mBó.

[7] His forces were later active in Wales[8] and perhaps in England, and English chronicler John of Worcester associates the Norwegian fleet (along with the Welsh ruler Gruffydd ap Llywelyn), with returning the exiled Ælfgar, Earl of Mercia to power.

At the same time, the rise in power of Godwin, Earl of Wessex and his sons, in particular Harold Godwinson, had also started representing a threat to Harald's claim.

[14] The exact year that Thorfinn Sigurdsson, Earl of Orkney died is not recorded anywhere, other than that it is stated in the Orkneyinga saga that it was in the later days of Harald Hardrada.

[16] Woolf has also proposed that Magnus may have played some part in the war in Scotland in 1057–1058, perhaps supporting Máel Coluim mac Donnchada against Lulach.

Before departing, he appointed Magnus as regent and king of Norway in his absence, and had his younger son Olaf accompany him on the expedition.

Olaf survived and returned to Norway with the remaining troops in early 1067, and was proclaimed king and co-ruler with his brother Magnus.