Merchant Ensign of the Ducal part of Slesvig-Holstein. (Slesvig-Holstein-Gottorp)
Own work by uploader, based on Flags Of The World;Historical Flags (Schleswig-Holstein, Germany). Used elements from File:Crown of a Prince of Denmark.svg and File:Royal Arms of Norway &amp; Denmark (1523-1535).svg by User:Sodacan.
Sir Iain