- The Norman Invasion of 1066 led by Duke William of Normandy brought about a major transformation in 'English' personal names. It became politically sound to baptise ones children with the French sounding names and naturally the most popular was William (which itself is Germanic in origin) or the French equivalent 'Guillaume'. The invasion also brought about the introduction of surnames, in this case the name development included Arnold Gilleme (1283 London), William Gilliam (1379 Yorkshire), Robert Gylam (1524 Suffolk). The modern spellings being Gillam, Gilham, Gilliam, Gillum and Gillham. The first recorded spelling of the family name is shown to be that of Peter Gillaume, which was dated 1276, The Pipe Rolls of Bedfordshire, during the reign of King Edward 1, "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.
Surnames reference. 2013.