Robert Duke

(male) One of the many French names of Germanic origin that were introduced into Britain by the Normans; it has since remained in continuous use. It is derived from the nearly synonymous elements hrōd ‘fame’ + berht ‘bright, famous’, and had a native Old English predecessor of similar form (Hreodbeorht), which was supplanted by the Norman name. Two dukes of Normandy in the 11th century bore the name: the father of William the Conqueror (sometimes identified with the legendary Robert the Devil), and his eldest son. It was borne also by three kings of Scotland, notably Robert the Bruce (1274–1329), who freed Scotland from English domination. The altered short form Bob is very common, but Hob and Dob, which were common in the Middle Ages and gave rise to surnames, are extinct. See also Rupert.

English and Irish: from Middle English duk(e) ‘duke’ (from Old French duc, from Latin dux, genitive ducis ‘leader’), applied as an occupational name for someone who worked in the household of a duke, or as a nickname for someone who gave himself airs and graces.