Gerhard I, Count of Holstein-Itzehoe
Gerhard I, Count of Holstein- Itzehoe( 1232 – 21 December 1290) was the only count of Holstein- Itzehoe.
Magnus III of Sweden
Magnus III (ca. 1240 – 18 December 1290) was King of Sweden from 1275 until his death in 1290.
Hedwig of Brandenburg
Hedwig of Brandenburg, also called Hedwig of Ballenstedt( – end of March 1203), a member of the House of Ascania, was Margravine of Meissen from 1156 until 1190 by her marriage with Margrave Otto II.
Adolph V, Count of Holstein-Segeberg
Adolph V, Count of Holstein- Segeberg( – 1308) was the ruling count of Holstein- Kiel from 1263 to 1273 and of Holstein- Segeberg from 1273 until his death.
Henry I, Count of Holstein-Rendsburg
Henry I, Count of Holstein- Rendsburg( 1258–1304) was the first Count of Holstein- Rendsburg.
Helvig of Schauenburg
Helvig of Schauenburg( 1398 – 1436), also known as Hedvig of Holstein and also Hedwig of Schauenburg, was a duchess of Schleswig and a countess of Holstein from the family of Schauenburg, and ancestor of the Danish Royal houses of Oldenburg and Schleswig- Holstein- Sonderburg- Glücksburg.
She was a daughter of Gerhard VI of Holstein- Rendsburg and his wife, Catherine Elisabeth of Brunswick- Lüneburg.
Her brother was Adolf VIII/ I, Count of Holstein/ Duke of Schleswig.
Through their father, they were cognatic descendants of King Eric V of Denmark while through their mother, they were cognatic descendants of King Abel of Denmark.
On 18 April 1417 Helvig was married to Prince Balthasar of Mecklenburg, who died of the plague in 1421.
In 1423 she was married to Dietrich, Count of Oldenburg.
From her second marriage she had the following children:
Albert II, Count of Holstein-Rendsburg
Albert II of Holstein( – 28 September 1403 in Dithmarschen( Ditmarsh)) was the ruling Count of Holstein- Rendsburg from his father's death, in 1381 or 1384, until 1397.
From 1397 until his death, he was Count of Holstein- Segeberg.
Hedwig of Gudensberg
Hedwig of Gudensberg, also known as" Hedwig of Hesse"( 1098 – 1148) was German regent: she served as regent of Thuringia during the minority of her son Louis II from 1140.
Hedwig of Holstein
Hedwig of Holstein or Helvig (1260–1324) was a Swedish queen consort, spouse of King Magnus III of Sweden.
She was the child of Gerhard I, Count of Holstein-Itzehoe (died 1290) and Elisabeth of Mecklenburg (died 1280).
John Adolf, Duke of Holstein-Gottorp
Johann Adolf of Holstein- Gottorp( 27 February 1575 – 31 March 1616) was a Duke of Holstein- Gottorp.

Question: What is the date of death of Hedwig Of Holstein's husband?
Answer: 18 December 1290