Your Irish Ancestry: Murphy (1992) VHS

The surname is a variant of two Irish surnames: "Ó Murchadha"/"Ó Murchadh" (descendant of "Murchadh"), and "Mac Murchaidh"/"Mac Murchadh" (son of "Murchadh") derived from the Irish personal name "Murchadh", which meant sea-warrior or sea-battler (muir meaning sea and cath meaning battle). According to historian C. Thomas Cairney, the O'Murphys were one of the chiefly families of the Uí Ceinnselaig who in turn were a tribe from the Dumnonii or Laigin who were the third wave of Celts to settle in Ireland during the first century BC. The O'Murphys as one of the chiefly families of the Uí Ceinnselaig is supported by John O'Hart in his 1892 Irish Pedigrees; or, The Origin and Stem of The Irish Nation. Murchadh is reported to have been gripped with a boiling awful rage, an extreme elevation and greatness of spirit and intellect when he joined the middle of the action and prepared to assail the foreign invaders, the Danes, after they had repulsed the Dal gCais. A gallantry and championship bird rose inside him and fluttered above his head and on his breath.[6] In modern Irish, "Ó Murchú" or Mac Murchú rather than Mac/Ó Murchadha", is used. "Murphy" is the most common surname in Ireland, the fourteenth most common surname in Northern Ireland, and the fifty-eighth most common surname in the United States