(the Holstein-Gottorps), a German ducal dynasty that ruled in the so-called ducal part (individual territories, the bulk of them lying in the north of Schleswig) of Schleswig-Holstein from 1544 to 1773; the younger line of the Danish royal house of Oldenburg.
From 1751 to 1818 the Gottorps occupied the throne in Sweden. In 1761 the Gottorp duke Karl Peter Ulrich became the Russian tsar under the name Peter III (ruled 1761–62). Pavel Petrovich, the future Pavel I, who was duke of Gottorp and the son of Catherine II. in 1773 traded the Gottorp possessions in Schleswig-Holstein for Oldenburg and Del-menhorst, which belonged to Denmark.