This notable and long-established surname is of early medieval Welsh origin, and derives from the ancient Welsh male given name "Rhydderch", a compound of the elements "rhi", ruler, and "derch", exalted. This name was borne by one of the North British rulers (flourished 590), Rhydderch Hael, called Hen, who fought with Urien, leader of the Britons in the 6th Century. In medieval documents of Wales the name is variously referred to as "Rodarchus, Rodercus" and "Rederech". The forms "Prydderch, Prytherch, Protherough" and "Prothero(e)" result from fusion of the Welsh patronymic suffix "ab, ap" with the name. In some instances, the Germanic personal name "Hrodric, Rodric(k)", from "hrod", renown, and "ric", power, replaced "Rhydderch", as a result of falsely equating the two names. An instance of the Anglicization of Rhydderch into Roderic occurs in the last century a propos of Pen Glasi, near Aberystwyth, "the present house was built by Roderic Richards, his father was Richard Rhydderch". One John ap Redragh was recorded in Caernarfonshire in 1538, and in 1581, William Prythergh, Proterugh or Protherough was entered in the Oxford University Register. On September 19th 1590, Elizabeth Prothero married a John Brown in Ludlow, Shropshire. A Coat of Arms granted to the Prothero family is a shield chequy azure and gold with a red annulet. The first recorded spelling of the family name is shown to be that of Treharn ab Retherech, which was dated 1292, in the "Subsidy Rolls of Cambridgeshire", during the reign of King Edward 1, known as "The Hammer of the Scots", 1272 - 1307. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.