From Thomas Walsh's History of the Irish Hierarchy:
Becmore in the barony of Duleek and about two miles south of Drogheda. Here are some remains of an ancient building which tradition informs us was a preceptory belonging to Kilmainham. Beaubec in the same direction as Beamore from Drogheda. In the reign of King John, Walter do Lacie, lord of Meath, did grant to the church of St. Mary and St. Lawrence of Beaubec all his land situate in Killokeran together with the liberty of keeping a boat free of toll.
A.D. 1332 King Edward I granted a license to the abbot of Beaubec in Normandy to assign to the abbot of Furnes the manor of Beaubec near Drogheda together with three messuages, sixty acres and a half of land and fifty seven shillings and nine pence annual rent arising from Marinston Renneles and the town of Drogheda on both sides of the river, also a fishery in the Boyne saving however to the lords of the fee their proper services.
A.D. 1348 King Edward in a charter dated May 4th recites and repeats the grant of Walter de Lacie and farther says that King Henry III had confirmed the same and that the abbot of Beaubec of the Cistercian order had afterwards with the king's license granted the aforesaid manor of Beaubec to the abbot of Furnes.