John II, Duke of Schleswig-Holstein-Haderslev (died 1580)

John the Elder was the only Duke of Schleswig-Holstein-Haderslev. The predicate the Elder is sometimes used to distinguish him from his nephew, John the Younger, who held Sønderborg from 1564 as a partitioned-off duke. As a co-ruler in the duchies of Holstein and of Schleswig, John the Elder is numbered as John II, continuing counting King John of Denmark as John I, Duke of Holstein and Schleswig.