Walter I, of the House of Grenier, was the lord of Caesarea in the Kingdom of Jerusalem from the 1120s until his death in the early 1150s.
Walter in the end never received Sidon and spent his last years heavily indebted and marginalized.
[1] They were the sons of Eustace I, lord of Sidon and Caesarea, who served as the constable of the Kingdom of Jerusalem and as regent during the captivity of King Baldwin II until his death on 15 June 1123.
[2] Historian Hans Eberhard Mayer argues that his fief, situated along the coast of the kingdom, was at first meant to pass undivided to the preferred twin, Eustace II.
[3] Walter came of age between 1127 and March 1129,[2] when a charter of King Baldwin II describes him as the lord of Caesarea.
His twin, Eustace II, had died, and Walter called himself lord of Caesarea and Sidon.