This rare and unusual surname is of Irish origin, and is a variant of Sloan(e), which is originally of Scottish origin, an Anglicization of the Gaelic personal name "Slaughadhan", a diminutive of "Slughadh", meaning expedition, raid. The surname may also be derived from the Gaelic "MacSleimhne", meaning "son of Sleimhne", a personal name of uncertain etymology, which was assumed by the Norman family of FitzStephen of Co. Cork. The name was formerly written Sleyney, and when first used as a surname carried the prefix Mac: the Fiants of 1569 and 1583 mention two MacSleyneys, both of Ballygeany, Co. Cork. Cork and Ross wills of the 18th Century include those of Slyne and Sline. The Christian name to which the Mac was first prefixed must be obsolete; the suggestion that it was Stephen would imply that "l" was substituted for "t", which is unlikely. The surname is rarely found recorded outside Co. Cork and the adjacent parts of Co. Waterford. Recorded in Ireland are the marriage of Bartholomew Slyne and Judith Dorgan on July 13th 1846 at St. Anne's, Shandon, Cork, and the birth of John, son of John Slyne and Julia Keilly, on June 17th 1866 at Ballyfeard, Co. Cork. The first recorded spelling of the family name is shown to be that of Elizabeth O'Slane, which was dated November 29th 1660, christened at Derry Cathedral, Templemore, Londonderry, during the reign of Richard Cromwell, known as "The Lord Protector", 1658 - 1660. 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.