Alphonso of Brienne
Alphonso of Brienne or Alphonse I de Brienne, called Alphonse d' Acre( c. 1228 – August 25, 1270) was the son of John of Brienne and Berengaria of León, born in Acre.
He was the Grand Butler of France in 1258.
By his marriage( bef. 1250) to Marie, Countess of Eu he became Count of Eu. He was also Grand Chamberlain of France, and died in Tunis on the Seventh Crusade.
He had at least two children by Marie:
William II, Count of Eu
William II, Count of Eu, feudal baron of Hastings( d. circa 1095) was a first generation Anglo- Norman nobleman, Count of Eu and rebel.
John II of Brienne, Count of Eu
John II of Brienne (died 11 July 1302 in Kortrijk) was the son of John I of Brienne, Count of Eu and Beatrice of Saint-Pol.
He succeeded his father as Count of Eu in 1294.
He married Jeanne, Countess of Guînes (d. 1331/32), the daughter and heir of Baldwin IV, Count of Guînes.
They had two children:
John was killed at the Battle of the Golden Spurs.
John I of Brienne, Count of Eu
John I of Brienne (died 12 June 1294) was the son of Alphonso of Brienne and Marie de Lusigan.
His mother was the heiress of Eu, Seine-Maritime, and he succeeded his father as Count of Eu in 1270.
He married Beatrice, the daughter of Guy III, Count of Saint-Pol.
They had:
John died at Clermont-en-Beauvaisis in 1294.
Erard I, Count of Brienne
Erard I, Count of Brienne( 1060 – 1114) was Count of Brienne at the end of the 11th century.
He was the son of Gautier I of Brienne, count of Brienne, and his wife Eustachie of Tonnerre.
In 1097 he fought in the First Crusade.
In 1110 he married Alix of Roucy- Ramerupt, daughter of André de Montdidier- Roucy, seigneur de Ramerupt.
They had 3 children:
Erard II, Count of Brienne
Erard II of Brienne( died 1191) was count of Brienne from 1161 to 1191, and a French general during the Third Crusade, most notably at the Siege of Acre.
He was the son of Gautier II, count of Brienne, and Adèle of Baudemont, daughter of Andrew, lord of Baudemont and Agnes of Braine.
His paternal grandparents were Erard I, Count of Brienne and Alix de Roucy.
During this siege he saw his brother André of Brienne die on 4 October 1189, before being killed himself on 8 February 1191.
Erard II's nephew was Erard of Brienne- Ramerupt.
Before 1166 he married Agnès of Montfaucon( † after 1186), daughter of Amadeus II of Montfaucon and of Béatrice of Grandson- Joinville.
Their children were:
Louis I, Count of Étampes
Louis d' Évreux, Count of Étampes( 1336 – 6 May 1400) was the son of Charles d' Évreux and Maria de La Cerda y Lara.
According to Froissart he was captured at Poitiers and ransomed.
He later served as one of the royal hostages given to Edward III of England to guarantee the Treaty of Brétigny.
In the 1390s, Louis was included in the entourage of John, Duke of Berry, who ultimately succeeded him in Étampes.
He married Jeanne( d. 1389), daughter of Raoul I of Brienne, Count of Eu and widow of Walter VI of Brienne, but they had no children.
Raoul II of Brienne, Count of Eu
Raoul II of Brienne( 1315 – 19 November 1350, Paris) was the son of Raoul I of Brienne, Count of Eu and Guînes and Jeanne de Mello.
He succeeded his father in 1344 as Count of Eu and Guînes, as well as in his post as Constable of France.
In 1340, he married Catherine( d. 1388), the daughter of Louis II, Baron de Vaud.
They had no children; one illegitimate son, Jean du Bois, Lord of la Maison Forte, was legitimized in 1395.
Guy Perry refutes this theory.
In 1346, he was captured in the taking of Caen by Thomas Holland, 1st Earl of Kent.
In 1350, he was allowed to return to France to attempt to raise money for his ransom.
Upon his arrival, he was seized and summarily executed by John II of France, for reasons that remain unclear, although it was rumoured that he had pledged the English the County of Guînes for his release.
Juan Alfonso de la Cerda
Juan Alfonso de la Cerda
( France, 1295- August 7, 1347) was Lord of Gibraleón, Huelva, Real de Manzanares and Deza.
He was the son of Alfonso de la Cerda, grandson of Ferdinand de la Cerda.
His mother was Matile of Brienne, daughter of John I of Brienne, Count of Eu. He married Maria Alfonso de Portugal( illegitimate daughter of King Denis of Portugal).
He served under Alfonso XI of Castile in the Siege of Algeciras( 1342- 1344), which culminated in the city's surrender in 1344.
Raoul I of Brienne, Count of Eu
Raoul I of Brienne( d. 1344, Paris) was the son of John II of Brienne, Count of Eu and Jeanne, Countess of Guînes.
He succeeded his father as Count of Eu in 1302, and his mother as Count of Guînes in 1332.
In 1329, he was named Constable of France, and he also held the office of Governor of Languedoc.
In 1315, he married Jeanne de Mello( d. 1351), Lady of Lormes and Château- Chinon.
They had three children:
He was killed in a tournament and was succeeded by his son Raoul.

Question: When did John Ii Of Brienne, Count Of Eu's father die?
Answer: 12 June 1294