Ó Duibhgeannáin
The Ó Duibhgeannáin (Irish pronunciation: [oː ˈd̪ɪvʲɡʲanɑːnʲ]) clan were a family of professional historians in medieval and early modern Ireland.
They originated in the kingdom of Annaly (also known as Conmaicne Maigh Rein) on the east bank of the Shannon (mostly situated in what is now County Longford) and later migrated into Connacht. Writing in 1921 the Irish historian, Fr. Paul Walsh stated that "The celebrated Dubhaltach MacFhirbhisigh ... informs us that the O Duigenans followed the profession of historiographers under the families of Clann Mhaiolruanaidh and Conmhaicne in Magh Rein, that is, with the Mac Dermotts and the MacDonoughs in the west, and with the O Farrells in the territory of Annaly."