| Anglo-Saxon Chronicle | An annalistic record of Anglo-Saxon history, first begun in late ninth-century Wessex but thereafter maintained in different redactions based out of different parts of the country, and covering important events from Caesar’s first British campaign down to the eleventh or twelfth century. It includes foreign events, such as the birth of Christ, but focuses on England. |
| Danegeld | The sum used to pay off Norse invaders in the period 991–1012 |
| Danelaw | A region comprising parts of Northumbria, East Anglia, and Mercia to which the Norse army under Guthrum agreed to withdraw in the 886 treaty with Alfred. Its southern border with Wessex ran along Watling Street, a rough diagonal from London to Chester. |
| Kings’ sagas | Old Norse prose biographies of Scandinavian kings |
| Legendary sagas | Old Norse prose adventure stories |
| Little Ice Age | A period c. 1300–c. 1700 during which many world regions were slightly cooler than before or after |
| Medieval Warm Period | Perhaps better termed Medieval Climate Anomaly, a period c. 900–c. 1250 during which some regions of the world, including the North Atlantic, were slightly warmer than the centuries preceding or following |
| Rus | A medieval group inhabiting the Novgorod and Kiev regions and thought to be the descendants of Swedish Vikings |
| Sagas of Icelanders | also known as family sagas, Old Norse prose accounts of Icelanders set roughly in the time between settlement (c. 871) and Christianization (c. 999), with some spillover on either end |
| Skaldic poetry | Stanzaic Old Norse poetry with highly complex metrical and alliterative conventions and frequent use of kennings, traditionally used to describe and praise the exploits of Scandinavian kings |
| St Brice’s Day Massacre | Learning of an alleged Danish plot on his life, King Æthelred II of England orders all Danes in England killed on November 13th, 1002. Actual killings may have been limited to Norse mercenaries in some centres outside the Danelaw. |