Recorded in a number of spellings as shown below, this notable and long-established surname is of early Welsh origin. It derives from the ancient male given name "Rhydderch", a compound of the elements "rhi", meaning ruler, and "derch", the exalted one! It was borne by one of the North British rulers who flourished around the year 590 a.d. This was Rhydderch Hael, who fought with Urien, the leader of the Britons in the 6th Century. In medieval documents of Wales the name is variously referred to as Rodarchus, Rodercus and Rederech, whilst the forms as Pluthero, Prothero, Protheroe and others result from fusion of the patronymic suffix "ab or ap" meaning son of, with the name. In some instances, the Germanic personal name Hrodric, Rodric(k), from "hrod", meaning renown, and "ric", power, replaced "Rhydderch", as a result of falsely equating the two names. One John ap Redragh was recorded in Caernarfonshire in 1538, and in 1581, William Prythergh or Protherough was entered in the Oxford University Register, whilst Charles Pluthero was a christening witness at St John the Baptist, Notting Hill, London, on November 12th 1875. The first recorded spelling of the family name is shown to be that of Treharn ab Retherech. This was dated 1292, in the Subsidy Rolls of Cambridgeshire, during the reign of King Edward 1st of England , 1272 - 1307. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.