Henry III, Duke of Mecklenburg
Henry III, Duke of Mecklenburg( 1337 – 24 April 1383) was Duke of Mecklenburg from 1379 until his death.
John VI, Duke of Mecklenburg
John VI, Duke of Mecklenburg( 1439 – 1474) was a Duke of Mecklenburg.
John III, Duke of Mecklenburg-Stargard
John III, Duke of Mecklenburg- Stargard( 1389 – after 11 November 1438) was from 1416 to 1438 Duke of Mecklenburg, Lord of Stargard, Sternberg, Friedland, Fürstenberg, and Lychen.
To distinguish him from John V, Duke of Mecklenburg, he is sometimes called" John the Elder".
Christopher, Duke of Mecklenburg
Christopher, Duke of Mecklenburg-Gadebusch (30 July 1537 – 4 March 1592) was a son of Albrecht VII, Duke of Mecklenburg.
He was Duke of Mecklenburg-Gadebusch, as well as administrator of Ratzeburg and of the Commandery of Mirow.
Eilika of Saxony
Eilika of Saxony( – 16 January 1142) was a daughter of Magnus, Duke of Saxony and a member of the Billung dynasty.
Through marriage to Otto of Ballenstedt, she was countess of Ballenstedt.
Euphemia of Sweden
Euphemia of Sweden (Swedish: "Eufemia Eriksdotter"; 1317 – 16 June 1370) was a Swedish princess, spouse of Albert II, Duke of Mecklenburg, Duchess consort of Mecklenburg, heiress of Sweden and of Norway, and mother of King Albert of Sweden.
Magnus I, Duke of Mecklenburg
Magnus I, Duke of Mecklenburg (1345 – 1 September 1384) was Duke of Mecklenburg from 1383 until his death.
Magnus was the third son of Duke Albert II of Mecklenburg and his wife Euphemia of Sweden, the sister of the King Magnus IV of Sweden.
Sometime after 1362, he married Elizabeth of Pomerania-Wolgast, daughter of Barnim IV, Duke of Pomerania.
Magnus had two children:
After the death of his brother Henry III in 1383, he ruled Mecklenburg jointly with Henry's son Albert IV until his own death in 1384.
Henry IV, Duke of Mecklenburg
Henry IV, Duke of Mecklenburg( 1417 – 9 March 1477) was from 1422 to 1477 Duke of Mecklenburg.
Eric II, Duke of Mecklenburg
Eric II, Duke of Mecklenburg (3 September 1483 – 21/22 December 1508) was Duke of Mecklenburg, a son of Magnus II, Duke of Mecklenburg, and his wife Sophie of Pomerania-Stettin.
Eric ruled Mecklenburg-Schwerin jointly with his brothers Henry V and Albert VII and his uncle Balthasar after his father's death on 27 December 1503.
Eric himself probably died on 21 December or 22 December 1508.
He was buried in the Doberan Minster in Bad Doberan.
He never married and died childless.
John I, Duke of Mecklenburg-Stargard
John I, Duke of Mecklenburg- Stargard( 1326 – 9 August 1392/9 February 1393), Duke of Mecklenburg from 1344 to 1352 and Duke of Mecklenburg- Stargard from 1352 to 1392.

Question: What is the date of birth of Magnus I, Duke Of Mecklenburg's mother?
Answer: 1317