Day of Valdemar and Reunion Day in Denmark

Valdemar (28 June 1170 – 28 March 1241), later remembered as Valdemar the Victorious (Valdemar Sejr), was the King of Denmark (being Valdemar II) from 1202 until his death in 1241.

After the Second War of Schleswig (Danish: Slesvig) in 1864, Denmark was forced to cede Schleswig-Holstein to Prussia, in a defeat that left deep marks on the Danish national identity. After this point Denmark adopted a policy of neutrality, as a result of which Denmark stayed neutral in World War I. After the defeat of Germany, the Versailles powers offered to return the then-German region of Schleswig-Holstein to Denmark. Fearing German irredentism, Denmark refused to consider the return of the area and insisted on a plebiscite concerning the return of Schleswig. The two Schleswig Plebiscites took place on February 10 and March 14, respectively. On July 10, 1920, after the plebiscite and the King's signature July 9 on the reunion document, Northern Schleswig (Sønderjylland) was recovered by Denmark, thereby adding 163,600 inhabitants and 3,984 km². The reunion day (Genforeningsdag) is celebrated every year June 15 on Valdemarsdag.