Recorded as Rat, Ratt and Ratter, this is a medieval English surname. Its derivation however is from the Olde French word 'raton' probably introduced at or after the famous Norman Conquest of England in 1066. Thereafter for some two hundred years, French was the official language of England. Diplomatically that remained so until the Napoleonic Wars 1795 - 1815, when the British gave up their claim to the throne of France, so that they could thereafter insist on speaking only English! This name may describe a rat catcher, as in Margeria le Ratonner in the Subsidy Tax rolls of the county of Suffolk in 1327. Apparently Margeria was not only a successul rat catcher, and one who was on more than nodding terms with the taxman at a time when few were, but a lady to boot! Earlier in the rolls known as the Testa de Neville in the year 1272, we have the recording of Jordan le Rat. According to the famous Victorian etymologist Canon Charles Bardsley writing in the year 1880, to call somebody a rat in medieval times was not regarded as uncomplimentary, in fact the reverse. The rat being praised for its stealth and cunning, as well no doubt being a pretty good street cleaner.