This unusual surname is of medieval Scottish origin, and is an abbreviated form of "Maccaig", itself a semi-Anglicization of the Old Gaelic "MacThaoig, MacThaidhg", son of Taoig, Tadhg, an ancient male given name meaning "bard, poet, philosopher". Tadhg was the name borne by the brother of Connor O'Connor, King of the Irish province of Connaught (died 973), and it appears as "Tathkr" and "Tand" in Norse Records relating to Ireland. In the process of Anglicization "MacThaoig" has acquired a number of variant forms including: MacCaig, MacCague, MacKaig, MacKeeg, MacKeig, MacKegg, MacKeague and Caig, the last mentioned form being widespread in Galloway and Ulster. One Andrew McCaig was noted in the Scottish Acts of Parliament, dated 1567, and Jennat Mackcaige was recorded in the Register of the Privy Council of Scotland in 1685. In the same year Archibald McKeag, a rebel in the Kilcheran parish, Kintyre, was entered in "The Commons of Argyll". The surname Caig is particularly well recorded in parish registers of Kircubbin, County Down, where on January 13th 1792, Ann, daughter of Henry Caig, was christened. Recordings of the name from Scotland include: John and Andrew Caig of the parish of Buittle, Kircudbrightshire (1684); John Caig, who married Margaret Stewart in Tinwald, Dumfries, on May 29th 1857; and Henrietta Caig, united in marriage with William Tait at Edinburgh parish, Midlothian, on July 20th 1866. The first recorded spelling of the family name is shown to be that of John Makkaig, of Wigtownshire, which was dated 1486, in the "Exchequer Rolls of Scotland", during the reign of King James 111 of Scotland, 1460 - 1488. 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.