North·um·bri·a (nôr-thŭm'brē-ə) An Anglo-Saxon kingdom of northern England formed in the seventh century by the union of Bernicia and Deira, Angle kingdoms originally established c. A.D. 500. Much of Northumbria fell to invading Danes in the ninth century and was annexed to Wessex in 954.
Anglo-Saxon kingdom of Norðhymbre, which lay "north" of the river Humber (L. Humbri fluminis, c.720), an ancient pre-English river name of unknown origin.