Duke of Lancaster
Monarchical
The dukedom of Lancaster is a former English peerage, created three times in the Middle Ages, which finally merged in the Crown when Henry V succeeded to the throne in 1413. Wikipedia
Past holders: John of Gaunt, Henry of Grosmont, Duke of Lancaster, and George Henry Harrison
Created by: Edward III (first creation); Edward III (second creation); Henry IV (third creation)
First holder: Henry of Grosmont
Former seat(s): Lancaster Castle
Peerage: Peerage of England