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 five children:

John died at Clermont-en-Beauvaisis in 1294.

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