Recorded as Gwilliam and Gwilliams, this very interesting surname is a combination of Welsh and Norman. It is late medieval and a curious dialectual formation of the Celtic personal name 'Gwyn', meaning 'The fair haired one,' and the Norman pre 7th century William, itself a compound which translates as 'mind-helmet'. The name development has included John Ap-Gwilym, the Chancellor of St. Davids in 1351, Lewis Gwilliam of Shropshire in 1631, and Robert Gwillim of East Cheshire in 1763. The first recording shows the complexity of Welsh names. It translates as Gwyn William, the son (ap) of John's (jan) son (kin). The plurality may also be an additional patronymic to give Williams - the son of William. The first recorded spelling of the family name is shown to be that of Jankyn ap Gwilliam which was dated 1391, in the register known as "The Extent of Chirkland," for the county of Shropshire in 1391 - 1393. This was during the reign of King Richard 11nd of England, known as "Richard of Bordeaux" 1379 -1399. Surnames became necessary when governments introduced personal taxation. In England this was sometimes known as the Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.