This famous surname is Irish. It is a developed form of the Olde Gaelic pre 10th century surname O'Muircheartaigh. The prefix O' indicates male descendant of, plus in this case a personal or perhaps occupational name "Muircheartach" meaning " The navigator". This sept originally closely associated with the O'Donoghues and the O'Mahonys, and belonged to County Kerry. Their territory lay on both sides of Castlemaine Harbour where they held great sway prior to the Anglo-Norman Invasion of 1170. Henry Augustus Moriarty (1815 - 1906) was true to his name, a renowned navigator who was highly acclaimed for his success in the recovery of first Atlantic telegraph cable which broke in mid-ocean in 1866. David Moriarty (1814 - 1877), and educated at Boulogne-sur-Mer and Maynooth, became the bishop of Kerry in 1856. A coat of arms granted to the Moriarty family depicts a black eagle displayed on a silver shield. On the crest is an armoured arm embowed holding a sword fessways entwined with a serpent, all proper. In heraldry, an eagle displayed is representative of speed and wisdom. The first recorded spelling of the family name is shown to be that of Teag O'Moriarty, a chief of the clan in County Kerry. This was dated 1210 when he married the daughter of a leading Anglo-Norman called Fitzgerald. This was during the reign of King Cathal and known as "Craobhdhearg", or Red Hand, The High King of Ireland,1198 - 1224.