The pronunciation varies according to a family's origins and linguistic heritage, but the most commonly used are the English "Pace", rhyming with "race", the Italian "PAH-chay", and the Maltese "PAH-ch".
Examples from parish registers include the marriage of Alice Pace to Thomas Picket in 1539 at St. Michael Bassishaw, and Alyse Paice who married John Garrot on August 16, 1573, at the church of St. Lawrence Pountney, both in the City of London.
The first is from an early medieval nickname for a mild-mannered and even-tempered man, derived from the Anglo-Norman-French and Middle English word "pace" or "pece", ultimately from the Latin "pax" or "pacis", meaning "peace".
[1] It has also been argued that Pace is an unusual surname of French origins, and the first recorded spelling of the family name is shown to be that of John Pais, which was dated 1219, in the "Register of the Freemen of Leicester", during the reign of King Henry III, known as "The Frenchman", 1216–1272.
The word sees popular usage in Ecclesiastical Latin, which today as in the Middle Ages pronounces it in the Italian manner.
Early bearers of this surname might have been bestowed with it because of their calm or reputation as peacemakers, or to those who spread peace in a religious sense.
The Dictionary of English Surnames[2] gives the origin of the English surname "Pace" as ME pais, OFr pais, Lat pax, "peace, concord, amity", and adds: "As ME pasches appears also as paisch, piece, peace, and Easter eggs are still called Pace eggs."