Question: When did Engelbert, Count Of Nevers's mother die?

William IV, Count of Nevers
William IV, Count of Nevers,( c. 1130 – Acre, 24 October 1168) Count of Nevers, Auxerre and Tonnerre( 1161 – 1168).
William III, Count of Nevers
William III, Count of Nevers( c. 1107 – 21 November 1161) was Count of Nevers, Auxerre and Tonnerre( 1148 – 1161).
He was born in Auxerre.
Eberhard I, Count of the Mark
Eberhard I( – 1308) was a German nobleman.
He was Count of the Mark from 1277 until his death.
He was the son of Engelbert I, Count of the Mark en Cunigonde of Blieskastel.
In 1277, Count Herman of Lohn abducted Eberhard's father Count Engelbert I, Count of the Mark near Tecklenburg and imprisoned him in the Castle of Bredevoort, where he later died.
In 1278 Eberhard took revenge and conquered the castle.
Eberhard also participated in the alliance against the Electorate of Cologne and gained the independence of the County of Mark from the Archbishop of Cologne after the victory in the Battle of Worringen in 1288.
He also obtained Brakel, Westhofen and Waltrop.
Elizabeth of Nevers
Elizabeth of Nevers (born: after 24 August 1439 in Nevers; died: 21 June 1483) was Duchess of Cleves from 1455 until her death, due to her marriage with John I of Cleves-Mark.
She was the matriarch of the house of Cleves-Nevers, and thus the Cleves line of the Counts and dukes of Nevers.
Because the territory was part of her inheritance, it fell to her son Engelbert after her death.
John II, Count of Nevers
John II, Count of Nevers( known as Jean de Clamecy, prior to acquiring title of" Count of Nevers"; 1415–1491) was a French noble.
Charles II, Count of Nevers
Charles II( died in Louvre in 1521) was Count of Nevers( 1506 – 1521).
He was son of Engelbert de La Mark and Charlotte de Bourbon- Vendome.
He belongs to the House de La Mark.
His father Engelbert, Count of Nevers( 1491 – 1506) was son of John I, Duke of Cleves( 1384 – 1404) and Elisabeth Countess of Nevers.
Elisabeth was great- granddaughter of Philip II duke of Burgundy.
Charles II succeeded his father in 1506.
He married in 1504 to Marie d' Albret, Countess of Rethel, daughter of Jean d' Albret and Charlotte Countess of Rethel.
Thus he became Count of Rethel jure uxoris.
They had:
Engelbert, Count of Nevers
Engelbert of Cleves, Count of Nevers (26 September 1462 – 21 November 1506) was the younger son of John I, Duke of Cleves and Elizabeth of Nevers, only surviving child of John II, Count of Nevers.
In 1481, he was sent with a large army to the Bishopric of Utrecht by his brother John II, Duke of Cleves where they successfully ousted David of Burgundy.
But after the Siege of Utrecht (1483) he had to flee, and Utrecht returned to the control of Burgundy.
He married Charlotte of Bourbon-Vendôme, daughter of John VIII, Count of Vendôme, circa 1489.
Their son
Engelbert became Count of Nevers and Eu in 1491 upon the death of his maternal grandfather John II, Count of Nevers.
His eldest brother John II (1458–1521) inherited Cleves.
Renauld II, Count of Nevers
Renauld II, Count of Nevers and Auxerre( died 1089) was the son of William I of Nevers, Count of Nevers and Ermengarde of Tonnerre.
He married Ida, daughter of Artald V, Count of Forez.
They had a child: Later he married Agnes of Beaugency.
They had:
William I, Count of Nevers
William I, Count of Nevers, was the son of Renauld I, Count of Nevers and Hedwig of France, Countess d' Auxerre.
In 1040 he succeeded his father as Count of Nevers and d'Auxerre and in 1065 he was also the Count of Tonnerre.
He married Ermengarde, daughter of Renauld, Count of Tonnerre about 1039.
William died at Nevers 20 June 1100.
William I and Ermengarde had six children:
Louis I, Count of Nevers
Louis I( 1272 – 22 July 1322) was" suo jure" Count of Nevers and" jure uxoris" Count of Rethel.
Louis was a son of Robert III, Count of Flanders, and Yolande, Countess of Nevers.
He succeeded his parents as Count of Nevers.
In December 1290, he married Joan, Countess of Rethel, and thus became her co-ruler in the County of Rethel.
They had two children:
He died in Paris shortly before his father and thus never succeeded his father as Count of Flanders.

Answer: 21 June 1483