Region and former duchy, northern Germany.
It was established as a duchy under the Ascanian dynasty in the 13th century. In 1728 George Louis, elector of Hanover , became its ruler, thereby attaching it to Hanover. It came under Prussia after the Danish-Prussian War of 1864. The duchy was abolished in 1918, and the region has been part of the state of Schleswig-Holstein since 1946.