Exploration of the North Atlantic
Iceland was discovered by Norse sailors in the early 9th century, though it may possibly have been settled by Irish monks before then. The first permanent migrants arrived in 874, and the Norse community rapidly grew until by 930 almost all of the arable land had been claimed.
The first settlements in southern Greenland were begun in the 980s by migrants from Iceland and Norway, including Erik the Red. At the time the island was uninhabited, but the Norsemen soon established trade relations with the Inuit peoples of nearby islands. Greenland accepted Norwegian overlordship in 1261, but the settlements were abandoned in 1377 when Álfur Þórsson relocated the Greenlanders to Vinland.
Vinland had been discovered in c.1000 by Bjarni Herjólfsson and Leif Eriksson, with the latter establishing a settlement at Leifsbudir. However, it was soon abandoned under Skraeling pressure, and a permanent Norse presence was not reestablished until 1377. For more information see Vinland and Colonization of Leifria and Vanaheim.
Scandinavia and the Balto-Slavic lands had already been trading for centuries. In 862 it is said that several warring tribes of the Ladoga region invited the Rus' Varangians under their chieftain Rurik to restore order. Rurik subsequently founded the city of Holmgard, later known as Novgorod, and soon had control over a vast swathe of eastern Europe.
His son Helgi moved the capital to Kiev. The Varangians gradually mingled with their Slavic subjects, and their state eventually evolved into Kievan Rus.
Viking raids on Albion began in 793, when the monastery of Lindisfarne in Bernicia was attacked and plundered.
In 865 the Norwegian king Ragnar Lodbrok was captured and executed by the forces of the British Kingdom of Ebrauc. In revenge, his three sons Halfdan, Ivar and Ubba gathered an army and invaded, capturing the kingdom by the end of the year. In 866 the army sailed south to Westfriesland, but was paid off by the king of Essex and instead prepared to attack the Britons.
After wintering in London, the army invaded Powys in the spring, defeating the combined forces of Powys, Dumnonia, Gwynedd and Gwent at the Battle of Caerlyr. All northern Wales bent the knee to the Norsemen, with only Dumnonia surviving of all the major kingdoms. However, after decades of warfare and coming close to extinction several times, Dumnonia would later manage to reconquer the north, uniting it into one kingdom for the first time.
Vikings also settled in remote parts of England, including Caithness, Mann and the isles of Sodor, and the links between England and Norway would remain strong for centuries to come. They also conquered much of the western coast of Eriu, founding the cities of Dublin and Cork and producing several prominent Irish clans of later generations.
In 911 the Viking leader Hrolfr Ragnvaldsson invaded Lyonesse and defeated the Frankish army at the Battle of Chartres. In the peace negotiations he was given the king's daughter Gisela as a bride and named as heir to the throne, thus beginning the Norman Dynasty of Lyonnaise kings.
For more information, see The Normans.