From an Old French name of Germanic origin, from fred, frid ‘peace’ + rīc ‘power, ruler’. It was adopted by the Normans and introduced into Britain by them, but did not survive long. Modern use in Britain dates from the 17th century, and it became more frequent in the 18th among followers of the Elector of Hanover, who in 1714 became George I of England. It was reinforced by the vogue for Germanic names in Victorian times.
English (but most common in Wales): from Lowis, Lodovicus, a Norman personal name composed of the Germanic elements hlod ‘fame’ + wīg ‘war’. This was the name of the founder of the Frankish dynasty, recorded in Latin chronicles as Ludovicus and Chlodovechus (the latter form becoming Old French Clovis, Clouis, Louis, the former developing into German Ludwig). The name was popular throughout France in the Middle Ages and was introduced to England by the Normans. In Wales it became inextricably confused with 2.