William I, Count of Nassau-Dillenburg
William I, Count of Nassau- Dillenburg( nicknamed" William the Rich",; 10 April
1487 – 6 October 1559) was a count of Nassau- Dillenburg from the House of Nassau.
His nickname" the Rich" refers to him having many children.
However, he owned a number of counties: Nassau- Dillenburg, Nassau- Siegen, Nassau- Dietz and Vianden.
William was born in Dillenburg as the younger son of Count John V of Nassau- Dillenburg and Landgravine Elisabeth, daughter of Landgrave Henry III of Hesse- Marburg and Anna of Katzenelnbogen.
He was the brother of count Henry III of Nassau- Breda and the father of William I of Orange.
His eldest son William the Silent inherited the principality of Orange in Southern France from his cousin René of Chalon, as well as the vast properties of the House of Nassau- Dillenburg in the Netherlands from his father, which Engelbert I of Nassau had received by marriage in 1403.
The early House of Orange- Nassau descends from William I., the Silent, while the later House of Orange- Nassau( and the Dutch royal family) descends in the male line from his younger brother John, Count of Nassau- Dillenburg, and from the latter's fifth son, Count Ernst Casimir of Nassau- Dietz, however in the female line also from William of Orange.
Elisabeth of Nassau-Dillenburg, Countess of Wied
Elisabeth of Nassau-Dillenburg (1 December 1488 – 3 June 1559 in Dillenburg) was a member of the House of Nassau.
She was a daughter of John V of Nassau-Dillenburg and his wife Elisabeth of Hesse-Marburg.
Her brothers were Henry III of Nassau-Breda, John of Nassau-Vianden-Dietz, Ernest of Nassau and William the Rich.
Her sister was Maria of Nassau.
Anna of Saxony
Anna of Saxony (23 December 1544 – 18 December 1577) was the heiress of Maurice, Elector of Saxony, and Agnes, eldest daughter of Philip I, Landgrave of Hesse.
Maurice's only son, Albert, died in infancy.
Anna was the second wife of William the Silent.
Anna was born and died in Dresden.
Her wealth drew many suitors; before the proposal of Orange in 1560, there were negotiations with the Swedish royal house.
She accepted the suit of William I of Orange, and they were married on 25 August 1561.
Otto I, Count of Nassau
Otto I of Nassau,( † between 3 May 1289 and 19 March 1290) was Count of Nassau and is the ancestor of the Ottonian branch of the House of Nassau.
Anna of Stolberg-Wernigerode
Countess Anna of Stolberg-Wernigerode (6 September 1819 − 17 February 1868) was a German noblewoman.
She was a deaconess and matron of the ("Bethany") hospital in Berlin.
Walram II, Count of Nassau
Walram II of Nassau,( – 24 January 1276), was Count of Nassau and is the ancestor of the Walramian branch of the House of Nassau.
Anna of Nassau-Dillenburg (1541–1616)
Anna of Nassau- Dillenburg( 21 September 1541 in Dillenburg – 12 February 1616 in Weilburg) was a daughter of Count William" the Rich" of Nassau- Dillenburg and his second wife, Juliana of Stolberg.
She married Count Albert of Nassau- Weilburg on 16 June 1559 and had the following children:
Henry I, Count of Nassau-Siegen
Henry I of Nassau- Siegen,( – between 13 July and 14 August 1343) was Count of Nassau- Siegen, a part of the County of Nassau, and ancestor of the House of Nassau- Siegen.
He comes from the Ottonian branch of the House of Nassau.
Countess Anna of Nassau
Countess Anna of Nassau (5 November 1563 – 13 June 1588) was a daughter of William the Silent and his second wife, Anna of Saxony.
She was the wife of William Louis, Count of Nassau-Dillenburg.
Frederick Augustus, Duke of Nassau
Friedrich August, Duke of Nassau, Prince of Nassau- Usingen( 23 April 1738 in Usingen – 24 March 1816 in Wiesbaden) was the last Prince of Nassau- Usingen and, jointly with his cousin, Friedrich Wilhelm of Nassau- Weilburg, first Duke of Nassau.
He died without surviving male issue and was succeeded by his cousin's son, Wilhelm.

Question: What is the date of birth of Countess Anna Of Nassau's mother?
Answer: 23 December 1544