What is "nordalbingia"

Nordalbingia (also Northern Albingia) was one of the four administrative regions of the medieval Duchy of Saxony, the others being Angria, Eastphalia, and Westphalia. The region's name is based on the Latin name Alba for the Elbe River and refers to an area predominantly located north of the Lower Elbe, roughly corresponding with the present-day Holstein region. Situated in what is now Northern Germany, this is the earliest known dominion of the Saxons.