de Lacy (Laci, Lacie, Lascy, Lacey, Lassey) is the surname of an old Norman family which originated from Lassy, Calvados. The family took part in the Norman conquest of England and the later Norman invasion of Ireland. The name is first recorded for Hugh de Lacy (1020–1085). His sons, Walter and Ilbert, left Normandy and travelled to England with William the Conqueror. The awards of land by the Conqueror to the de Lacy sons led to two distinct branches of the family: the northern branch, centred on Blackburnshire and west Yorkshire was held by Ilbert's descendants; the southern branch of Marcher Lords, centred on Herefordshire and Shropshire, was held by Walter's descendants.