This very unusual name is apparently either an "Anglicized" variant of the Old French heraldic surname "Gilfaut" from the Forres region of France, or it is a dialectal variant of Gillford or Gillfford. The later are themselves variants of "Gyldeford", the modern town of Guilford in Surrey. Because the first surname recording as shown, is not before the mid 18th Century, it is not possible to be absolutely positive on the origin but it would seem to French Catholic, as against French Huguenot. The examples of the recording include the following, Anna Gilfoy who married Joseph Bellaudi at Lincolnshire Inn Fields on September 16th 1770, whilst on Christmas Day in 1817, which used to be a popular day for weddings, Elizabeth Gilfoy married John Herbert Reeves at the church of St. Ann's, Soho, Westminster. The first recorded spelling of the family name is shown to be that of Cornelli Gilfoy, which was dated February 20th 1763, a witness at Lincoln Inn Field, London, during the reign of King George 111, "Farmer George", 1760 - 1820. 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.