John I of Brienne, Count of Eu

John I of Brienne (born 1246 died 12 June 1294) was the son of Alphonso of Brienne and Marie de Lusigan.

[1] His mother was the heiress of Eu, Seine-Maritime, and he succeeded his father as Count of Eu in 1260.

(both The Chronique des comtes d’Eu and the necrology of the church of Eu refer to Alphonso as either "Mister Alphons" or "Alphons, son of the king of Jerusalem," leading one to believe without the title of "count" it was passed to his son upon his wife's death in 1260.)

He married Beatrice, the daughter of Guy III, Count of Saint-Pol.

[1] They had: John died at Clermont-en-Beauvaisis in 1294.