Mt. Grellan alikuwa Mkristo hodari wa karne ya 5 na karne ya 6 aliyejenga makanisa mbalimbali nchini Ireland. Tangu kale anaheshimiwa na Wakatoliki kama mtakatifu. Sikukuu yake huadhimishwa tarehe 10 Novemba. Watakatifu wa Agano la Kale Orodha ya Watakatifu Wakristo Orodha ya Watakatifu wa Afrika Orodha ya Watakatifu Wafransisko See Stokes, p. 215, which refers to Grellán from Craeb Grelláin in Connaught in the east of Mag Luirg. Egan, P. K. (1953). Ballinasloe: A Historical Sketch. Ballinasloe Tóstal Council.  O'Donovan, John (1843). Tribes and Customs of Hy Many Commonly Called O'Kellys Country. Irish Archaeological Society.  Stokes, Whitley (1895). The Martyrology of Gorman: Edited From A Manuscript In The Royal Library Brussels.