Original: The former English name was Sleswick-Holsatia, the Danish name is Slesvig-Holsten, the Low German name is Sleswig-Holsteen, and the North Frisian name is Slaswik-Holstiinj.
Simplified: The Danish name is Slesvig-Holsten, the Low Saxon name is Sleswig-Holsteen and the Frisian name is Sleeswyk-Holstein.