This interesting surname has two main Irish septs of entirely different origin and location. One is "Mac Amhalghaidh", from the Gaelic prefix "mac" meaning son of, plus "Amhalghaidh" a form of the Old Irish personal name Auley. This sept was at one time of considerable importance, being lords of a wide territory in the west of Co. Westmeath and north of Offaly; in the Elizabethan Fiants this is called "Mc Gawley's Country". They are descended from Niall of the Nine Hostages, their surname being taken from his descendant Auley, who flourished in the 13th Century. The other sept was called in Irish Mac Amhlaoibh. They are a branch of the Mac Guires and belong to Co. Fermanagh, where they have given their name to the barony of Clanawley. The same Gaelic form is used by the Scottish clan of Mac Aulay. Many of the Irish born M(a)c Auleys and M(a)c Auleys, particularly those living in the counties adjacent to Belfast, are descendants of Scottish settlers in Ulster. The outstanding figure of the name in Irish history is Catherine M(a)c Auley (1787-1841), foundress of the Order of Mercy. The first recorded spelling of the family name is shown to be that of Owar Mc Aulay of Lennox, which was dated 1326, "The Exchequer Rolls of Scotland", during the reign of Robert the Bruce of Scotland, 1306 - 1329. 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.