From Wikipedia

Normans

The Normans were the people who gave their name to Normandy, a region in northern France. They were descended from Viking conquerors of the territory and the native population of mostly Frankish and Gallo-Roman stock. Their identity emerged initially in the first half of the 10th century, and gradually evolved over succeeding centuries. The name "Normans" derives from Nortmanni (Northmen), after the Vikings who founded Normandy.

They played a major political, military, and cultural role in medieval Europe and even the Near East. They were famed for their martial spirit and eventually for their Christian piety. They quickly adopted the Romance language of the land they settled off, their dialect becoming known as Norman, an important literary language. The Duchy of Normandy, which they formed by treaty with the French crown, was one of the great large fiefs of medieval France. The Normans are famed both for their culture, such as their unique Romanesque architecture, and their musical traditions, as well as for their military accomplishments and innovations. Norman adventurers established a kingdom in Sicily and southern Italy by conquest, and a Norman expedition on behalf of their duke led to the Norman Conquest of England. Norman influence spread from these new centres to the Crusader States in the Near East, to Scotland and Wales in Great Britain, and to Ireland.

In Russian historiography, the term "Norman" is often used for the Varangians, as for example in the term "Normanist theory". In French historiography too, the term is often applied to the various Viking groups that raided France in the 9th century before settling down to found Normandy.