Is Britain descended from the Nordic people?

The official name of the main ethnic group in Britain is "Anglo-Saxon", but this is limited to England. The ethnic groups in Scotland, Ireland and Wales are Scots, Irish and Welsh. However, the ancestors of these three ethnic groups also had the same name in ancient times: "Celtic". British history began in the Roman Empire, when the Roman general Caesar crossed the sea and entered the British Island. The island began to contact with Roman civilization, and the British have their own civilization history since then. After entering England, the game was Celtic. Later, the national fortunes of the Roman Empire declined in the later period. Now Germany's "Germans" rushed into the territory of the Roman Empire, disintegrated the Roman Empire, established a series of small Germanic countries, and laid the common lineage of the main nationalities in Western Europe today, which is called "Germanic Migration" in history. The Anglo-Saxons in England are the result of this great migration. Modern British people have two main ethnic origins: Germans and Celts.