Schleswig-Holstein-Sonderburg-Beck

It consisted of August Philipp, Duke of Schleswig-Holstein-Sonderburg-Beck (1612–1675) and his male-line descendants.

Schleswig-Holstein-Sonderburg-Glücksburg, to which several present-day royal houses belong, is the new name of Schleswig-Holstein-Beck.

The members of the line were titular dukes of Schleswig and Holstein, and they were originally not ruling.

The line is named after Beck, a manor in Ulenburg, Bishopric of Minden (today Löhne, North Rhine Westphalia).

August Philipp bought this manor from the Count of Oldenburg, and he made it his residence.