Since the foundation of this ducal line by Phillip, the second youngest son of Johann the Younger, the members of the House of Schleswig-Holstein-Sonderburg-Glücksburg have carried a coat of arms. Since 1559 almost all Dukes of Schleswig and Schleswig-Holstein have carried that coat of arms. In the inescutcheon two red chevrons against a golden background represent Oldenburg, while a golden cross with a blue background represents Delmenhorst.
The coat of arms bears a golden lion on a red background holding a silver halberd with a golden haft, representing Norway’s heritage. On the left with two blue lions above each other on a golden background, representing Schleswig, next to it. Below is a silver nettle leaf on a red background from Holstein, a silver horse with an armour-clad horseman from Dithmarschen to the right of it, and a silver swan with a golden crown from Stormarn below.