Magnus III of Norway in the context of Coronations in Norway

The Battle of Stamford Bridge (Old English: Gefeoht æt Stanfordbrycge) took place at the village of Stamford Bridge, East Riding of Yorkshire, in England, on 25 September 1066, between an English army under King Harold Godwinson and an invading Norwegian force led by King Harald Hardrada and the English king's brother Tostig Godwinson. After a bloody battle, both Hardrada and Tostig, along with most of the Norwegians, were killed. Although Harold Godwinson repelled the Norwegian invaders, his army was defeated by the Normans at Hastings less than three weeks later.

The battle has traditionally been presented as symbolising the end of the Viking Age, although major Scandinavian campaigns in Britain and Ireland occurred in the following decades, such as those of King Sweyn Estrithson of Denmark in 1069–1070 and King Magnus Barefoot of Norway in 1098 and 1102–1103.

The Norman invasion of Wales began shortly after the Norman conquest of England under William the Conqueror, who believed England to be his birthright. Initially (1067–1081), the invasion of Wales was not undertaken with the fervour and purpose of the invasion of England. However, a much stronger Norman invasion began in 1081 and by 1094 most of Wales was under the control of William's son and heir, the later King William II. The Welsh greatly disliked the "gratuitously cruel" Normans, and by 1101, had regained control of the greater part of their country under the long reign of King Gruffudd ap Cynan, who had been imprisoned by the Normans for twelve years before his escape.

In one incident, Gruffudd had some indirect help from King Magnus III of Norway (Magnus Barefoot) who attacked the Normans briefly off the Isle of Anglesey in northwest Wales near Ynys Seiriol, killing Hugh of Montgomery, 2nd Earl of Shrewsbury.

The Treaty of Perth, signed 2 July 1266, ended military conflict between Magnus the Lawmender of Norway and Alexander III of Scotland over possession of the Hebrides and the Isle of Man.

The Hebrides and the Isle of Man had become Norwegian territory during centuries when both Scotland and Norway were still forming themselves as coherent nation-states, and Norwegian control had been formalised in 1098, when Edgar of Scotland signed the islands over to Magnus III of Norway. In Norwegian terms, the islands were the Sudreys, meaning Southern Isles.

Jón Loftsson (Modern Icelandic: [ˈjouːn ˈlɔf(t)sɔn]; Old Norse: Jón Loptsson [ˈjoːn ˈloptsˌson]; c. 1124–1197) was chieftain of Oddi at Rangárvellir in the south part of Iceland.

Jón Loftsson was a member of the Oddaverjar family clan. His parents were Loftur Sæmundsson and Þóra Magnúsdóttir.His paternal grandfather was Sæmundur Sigfússon (Sæmundr fróði). His maternal grandfather was King Magnus III of Norway. He was educated at Konghelle (Kungahälla) in Bohuslän (Båhuslen) which at that time a royal center of the Kingdom of Norway. Jón Loftsson was married to Halldóra Brandsdatter with whom he had several children.

East Loch Tarbert, Argyll is a small sea loch on the eastern side of the Kintyre Peninsula, in Argyll and Bute, west of Scotland. It is a part of the much larger Loch Fyne. The village of Tarbert is distributed along the shores of the loch. East Loch Tarbert is separated from West Loch Tarbert by an isthmus, that is only 1.5 kilometres (0.93 mi) long.

According to Snorri Sturluson's Heimskringla, Magnus Barefoot, King of Norway, had his longship dragged across this isthmus as part of a campaign to increase his possessions in the Hebrides. He made an arrangement with King Malcolm III of Scotland that he could take possession of land on the west coast around which a ship could sail. Magnus declared that Kintyre had "better land than the best of the Hebrides", and by taking command of his ship's tiller and "sailing" across the isthmus he was able to claim the entire peninsula, which remained under Norse rule for more than a dozen years as a result.