This notable surname, widely recorded in 19th Century Church Registers of Ulster and Scotland, is a an Anglicized form of the Old Gaelic "O'Dochartaigh", descendant of Dochartach. This was a personal byname with the strange meaning of "hurtful, or injurious". Traditionally, Irish family names are taken from the heads of tribes, revered elders, or some illustrious warrior, and are usually prefixed by "Mac", denoting "son of", or "O", grandson, male descendant of. Originating in the barony of Raphoe, County onegal, this large and powerful sept were of the same stock as the illustrious O'Donnells of Tirconnell (County Donegal), one of the most famous septs in Irish history. By the 14th Century the O'Dochartaigh chiefs had extended their territory till they became lords of Inishowen, and their headquarters was on the Inishowen Peninsula. In 1208, one David O'Doherty, a chief of Cinel Conaill, was killed in battle, and from him descend the MacDaibhid or MacDevitts of Inishowen. The power of the O'Dohertys was greatly reduced following the ill-timed rebellion of 1608, led by Sir Cahir O'Doherty, and several of the sept fled to Scotland, the Isle of Man and England where the name was variously Anglicized as Do(u)gherty, Daugherty, Docherty and Docharty. On May 6th 1817, the birth of a daughter to Mrs. Mary Docherty was recorded at Drumbo, County Down, and on September 4th 1843, a son, John, was born to Peter Docherty and Janet Clark, in Midlothian, Scotland. The first recorded spelling of the family name is shown to be that of Donnall O'Dochartaigh, which was dated 1119, in "Manx Names", by A.W. Moore, during the reign of High Kings of Ireland "with opposition", 1022 - 1166. 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.