Why is the surname Gray more common than the surname Grey in the UK?

Solution 1:

There is a long discussion of “grey” vs “gray” in the OED. Historically, greig goes back to Old English, while grae, grai does not show up until Middle English. “Grey” is the preferred spelling in modern British English, but people can spell their names anyway they like, and there is perhaps an attraction in spelling your name differently from a common colour adjective.

By the way: French gris is not the antecedent of English “grey”, as Johnson seems to have believed; it is a Germanic loanword.

Solution 2:

There is an excellent web resource at www.surnamedb.com. It says about the surname Gray:

Recorded as Gray, Graye, Grey, Greye, de Grey, MacGray, McGray, McGrah, McGreay, McGrey, and possibly others, this ancient Anglo-Scottish surname has at least two possible origins. The first was Old English and a nickname or personal name for a man with grey hair or beard, from the pre 7th century word "graeg", meaning grey. Although the name means the same in Scotland and Ireland,name holders there took their name from the early Gaelic word "riabhach" which also means brindled or grey. The second separate origin is French and locational. As such it is from the village of Graye in Calvados, Normandy, and was introduced into the British Isles after the famous Conquest of 1066. The village was called from the Roman personal name "Gratus" meaning welcome, with the suffix "acum," a settlement. Early recordings of the surname include Baldwin Grai, in the Pipe Rolls of Berkshire in 1173, and Henry de Gray, in the Pipe Rolls of Nottinghamshire, dated 1196. Other examples include Henry Gray and Jone Darby married at St. Margaret's, Westminster, on November 30th 1539 and Catherine MacGray, christened at Endell Street lying in hospital, city of London on March 17th 1763. Thomas Gray (1716 - 1771), the poet, was most well known for his "Elegy in a Country Churchyard", published in 1751. The first recorded spelling of the family name is shown to be that of Anschitill Grai. This was dated 1086, in the Domesday Book of Oxfordshire, during the reign of King William 1st, known as "The Conqueror", 1066 - 1087. Surnames became necessary when governments introduced personal taxation. In England this was sometimes known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.