This interesting surname is an Anglicized form of the Old Gaelic adjective "Caomhanach" denoting association with St. Caomhan or St. Kevin. In this case, the first namebearer was Donal, son of Diarmuid Mac Murrough 12th Century King of Leinster, who was sent by his father to be educated at Kill Caomhan, i.e. St. Kevin's Church, County Wexford. Perhaps to distinguish him from others of the same name, the king's son was called "Caomhanach". Art Mac Murrough, 14th Century King of Leinster, was the first to use the agnomen Kavanagh, from the above "Caomhanach", meaning "handsome by birth", along with his surname. Interestingly, Kavanagh is one of the very few ancient Gaelic Irish surnames having neither the prefix "Mac" or "O". The territory of the Kavanagh's lay in the adjoining Counties of Carlow and Wexford, and the name is still most widespread in that part of south East Leinster. Eileen, daughter of a 13th Century Kavanagh chief, is invoked in the well known song "Eileen Aroon", and one, Art Kavanagh was companion to Hugh O'Neill in his dramatic escape from Dublin Castle in 1590. Patrick Kavanagh, known as "the Wordsworth of County Monaghan", is one of the best known Irish poets of the 20th Century. The first recorded spelling of the family name is shown to be that of Art Mac Murrough Kavanagh, King of Leinster, which was dated 1376 - 1417, in "Records of the Province of Leinster", during the reign of King Richard 11 of England, known as "Richard of Bordeaux", 1377 - 1399. 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.