From an Old French name, Arnald, Arnaud, which is of Germanic (Frankish) origin, from arn ‘eagle’ + wald ‘ruler’. It was adopted by the Normans and introduced to Britain by them. An early saint of this name, whose cult contributed to its popularity, was a musician at the court of Charlemagne. He is said to have been a Greek by birth; it is not clear when and how he acquired his Germanic name. It never entirely went out of use in England, and came back into more general favour in the 19th century, along with several other medieval Germanic names.