|Count of Hainaut, Holland and Zeeland|
|Died||22 August 1304 (aged 56–57)|
|Spouse(s)||Philippa of Luxembourg|
|Father||John I of Avesnes|
|Mother||Adelaide of Holland|
John II, born 1247, was the eldest son of John I of Hainaut and Adelaide of Holland. He was Count of Hainaut from 1280 to his death and Count of Holland from 1299 until his death. John continued the war between the House of Dampierre and the House of Avesnes against Count Guy of Flanders for imperial Flanders.
John II became count of Holland in 1299 upon the death of his maternal cousin John I. The personal union he established between Hainaut and Holland–Zeeland lasted for another half-century. John I's father, Floris V, had been fighting against Flanders for Zeeland. He sought help of France against Flanders. The French defeated the Flemish in 1300 and 1301. The rebels in Zeeland were defeated as well. John's brother, Guy of Avesnes, became bishop of Utrecht. Thus, all his main enemies were gone.
The tide changed dramatically after a Flemish uprising and the defeat of the French army at the Battle of the Golden Spurs in 1302, where John's eldest son was killed fighting for the French. The Flemish attacked Hainaut and Zeeland supported by the dissatisfied population there. Guy of Namur defeated John's son, William, in a battle on the island of Duiveland. Bishop Guy of Utrecht was taken prisoner. Guy of Namur and Duke John II of Brabant conquered most of Utrecht, Holland, and Zeeland. Guy of Namur was finally defeated in 1304 by the fleet of Holland and France at the naval Battle of Zierikzee. John II regained most of his authority when he died in the same year.
- John, Lord of Beaumont, Count of Ostervant. Killed in battle (11 July 1302).
- Henry, a canon in Cambrai, (died 1303).
- William I, Count of Hainaut (c. 1286 – 7 June 1337) He succeeded his father in 1304. Married Joan of Valois, daughter of Charles, Count of Valois.
- John of Beaumont (1288 – 11 March 1356). He was married to Margaret, Countess de Soissons.
- Margaret (died 18 October 1342), married Robert II of Artois, who was killed at the Battle of the Golden Spurs, 11 July 1302.
- Alice or Alix (d. 26 October 1317), who married 1290 Roger Bigod, 5th Earl of Norfolk, by whom she had no issue.
- Isabelle (died 1305), married Raoul de Clermont Lord of Nesle, who was killed in battle at the Battle of the Golden Spurs, 11 July 1302.
- Joan, a nun at Fontenelles.
- Mary of Avesnes (1280–1354), married Louis I, Duke of Bourbon.
- Matilda, Abbess of Nivelles.
John's illegitimate children were:
- Detlev Schwennicke, Europäische Stammtafeln: Stammtafeln zur Geschichte der Europäischen Staaten, Neue Folge, Band II (Marburg, Germany: Verlag von J. A. Stargardt, 1984), Tafel 22
- Johan C H Blom, History of the Low Countries (New York: Berghahn Books, 2006), p. 58
- Johan C H Blom, History of the Low Countries (New York: Berghahn Books, 2006), pp. 57–8
- Elizabeth Moore Hunt, Illuminating the Borders of Northern French and Flemish Manuscripts, 1270 – 1310 (New York: Routledge, 2007), p. 125
- M. A. Pollock, Scotland, England and France After the Loss of Normandy, 1204-1296, (The Boydell Press, 2015), xv.
- Gary Boyd Roberts, The royal descents of 600 immigrants to the American colonies or the United States : who were themselves notable or left descendants notable in American history: with a 2008 addendum, coda, and final addition (Baltimore: Genealogical Publishing Co., 2008)[page needed]
- Orlanda Lie and Joris Reynaert eds., Artes in context. Opstellen over het handschriftelijk milieu van Middelnederlandse artesteksten (Hilversum 2004), 67.