Hi, from research I did in the 1970's I understood that the name was of Norman origin. Here's how:the earliest groupings af the name (phonetically spelt Pacee, and only in 1784 in the case of my direct ancestor one Thomas Pacy/Peacey from Bisley, Glos. was the modern spelling adopted)I found based up and down the river Severn in Gloucestershire, this appeared to be the earliest stronghold. The surname was supposed to have originated from Pacy sur Eure, a small town in Normandy about 30 miles north of Paris. Following the Norman invasion William fitzOsbern was made first Earl of Hereford which encompassed the Welsh Marches and included the land up and down the Severn, right down as far as Somerset. Amongst his holdings in Normandy was (surprise, surprise) Pacy sur Eure! In 1071 William fitzOsbern was assasinated and the Earldom of Hereford was passed to someone else, thus the link with Pacy sur Eure was in place for 5 years only, and it is probable that at some point during these 5 years "the ancestor" came over. It being common at that time to reward ones vassals with land! This was the version I uncovered. I am unaware of the Viking or Saxon possibilities, what do people think?