Recorded as Dealey, Deeley, Deelay, Delaye, Delay, Dealy and possibly others, this was always thought to be an Irish surname. If so it is derived from the pre 10th century Gaelic surname O' Duibhghiolla, the prefix O' meaning "male descendant of", with dubh, dark haired or dark skinned, and giolla, a boy or lad. The vast majority of Irish surnames were originally nicknames given to the first chief of the clan, and he was presumably significantly dark haired or dark complexioned or both. It is said that the clan originated in County Galway, whilst over the water in England there are a large number of nameholders particularly in the city of Birmingham. However the surname is well recorded in England in Elizabethan times, and we now believe that the origin can be either Irish as shown, or for many nameholders French. If the latter, it is from the surname 'de Laye', as shown in the recording of David de Laye at St Martins in the Field, Westminster, in 1569. Other examples of recordings include John Delaye who married Elisabeth Boner at St Bartholomew the Less, on November 24th 1602, and William Dealey who was christened at St. Andrew's Holborn, in the city of London on December 11th 1626. In Ireland itself where most early registers and records were destroyed by the IRA in 1922, we have the recording of Eleanor, the daughter of Michael and Eleanor MacDaniel Deeley, who was christened at St. Mary's church, Limerick, on August 3rd 1780. 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.