Eric II, Duke of Schleswig
Eric II Valdemarsøn( c. 1290 – 12 March 1325) was Duke of Schleswig from 1312 until his death in 1325.
He was the only son of Valdemar IV, Duke of Schleswig.
Valdemar III, Duke of Schleswig
Valdemar III Abelsøn (died 1257) was Duke of Schleswig from 1253 until his death in 1257.
He was the eldest son of King Abel of Denmark, Duke of Schleswig and Matilda of Holstein.
Abel, Lord of Langeland
Abel Abelsøn( 1252 – 2 April 1279), Lord of Langeland, was the third son of King Abel of Denmark, Duke of Schleswig and younger brother of Valdemar III, Duke of Schleswig and Eric I, Duke of Schleswig.
As a member of the ducal family, he held several fiefs in Southern Denmark.
Valdemar III of Denmark
Valdemar III( 1314–1364) was king of Denmark from 1326 to 1329, while he was underage; he was also Duke of Schleswig as Valdemar V in 1325 – 26 and from 1330 to 1364.
He was a rival king set up against the unsuccessful Christopher II and was widely opposed by his subjects.
His term was ended when he abdicated.
Sometimes the earlier King Valdemar the Young( c. 1209 – 1231) is also referred as Valdemar III.
Valdemar the Young
Valdemar the Young( – 28 November 1231) was King of Denmark from 1218 until his death.
Valdemar was the eldest son and co-ruler of King Valdemar II of Denmark by his first wife, Dagmar of Bohemia.
He did not outlive his father so was never a sole monarch.
He is sometimes referred to as Valdemar III for example his tombstone reads in" Valdemar the Third, King of Denmark, son of Valdemar the Second".
Although Valdemar III is more commonly used to denote a later king, Valdemar of Schleswig.
Albert, Duke of Schleswig-Holstein
Albert, Duke of Schleswig- Holstein( Albert John Charles Frederick Alfred George; 26 February 1869 – 27 April 1931), was a grandson of Queen Victoria.
He was the second son of Victoria's daughter, Princess Helena, by her husband Prince Christian of Schleswig- Holstein.
He was the head of the House of Oldenburg and also the House of Schleswig- Holstein- Sonderburg- Augustenburg and the Duke of Schleswig- Holstein between 1921 and 1931.
Matilda of Holstein
Matilda of Holstein or Mechthild (1220 or 1225 – 1288 in Kiel) was a Danish queen consort, married to King Abel of Denmark and later to Birger Jarl, Regent of Sweden.
Wilhelm Friedrich, Duke of Schleswig-Holstein
Friedrich, Duke of Schleswig- Holstein- Sonderburg- Glücksburg, from 1934 Duke of Schleswig- Holstein( 23 August 1891 – 10 February 1965), was the Duke of Schleswig- Holstein and Head of the House of Oldenburg from 21 January 1934 until his death on 10 February 1965.
Eric Longlegs, Lord of Langeland
Erik Eriksøn, also known as Eric Longlegs,( 1272 – 1310), Lord of Langeland, was the second son of Eric I, Duke of Schleswig and younger brother of Valdemar IV, Duke of Schleswig.
Friedrich Ferdinand, Duke of Schleswig-Holstein
Friedrich Ferdinand of Schleswig- Holstein- Sonderburg- Glücksburg( 12 October 1855 – 21 January 1934) was the fourth Duke of Schleswig- Holstein- Sonderburg- Glücksburg and became Duke of Schleswig- Holstein in 1931.

Question: Where did Valdemar Iii, Duke Of Schleswig's mother die?
Answer: Kiel