Eustace Grenier

Eustace I Granier, also known as Eustace Grenier or Eustace Garnier, called in Latin Eustachius Granarius in the charters (born around 1070 and died on 15 June 1123), was a Flemish crusader who took part in the First Crusade. He became lord of Caesarea in 1101, lord of Sidon in 1110, and in April 1123, was elected constable and bailiff of Jerusalem during the captivity of Baldwin II of Jerusalem. Shortly before his death, he defeated a Fatimid army at the Battle of Yibneh near Ibelin.

Grenier is a presumed member of the knights of the diocese of Thérouanne in the County of Saint-Pol who accompanied Baldwin of Boulogne to the Holy Land, as he is quoted in a text written during his life in their honour.