For background on how the map was made (and its flaws), see the relevant blog entry.
|Hagan||numerous: Tyrone-Armagh-Down etc. Ir. Ó h-Ágáin, originally Ó h-Ógáin, óg meaning young. An important sept of Tyrone. Also stands for Ó h-Aodhagáin, a diminutive of the personal name Aodh meaning "fire". Aitken is a synonym. IF & SGG.|
|Heggan||rare: Antrim. Variant of Hagan, q.v.|
|Ó h-Ágáin||Hagan: líonmhar, Oirthear Uladh & rl. Go bunaidh, Ó h-Ógáin ach deir Mac Giolla Iasachta gur ionann é agus Ó h-Aodhagáin. Clann a bhí suite ag Tullaigh Óg agus a dhéanfadh na Niallaigh a inshealbhú mar thaoisigh. IF &MIF.|
|Ó h-Aodhagáin||Hagan, Egan &rl: an-líonmhar tríd an dtír (Hagan in Ultaibh). Deineadh Fegan de chomh maith. Bhí clann tábhachtach in Oirghialla agus ceann eile in Éile Uí Chearbhaill (Uíbh Fhailí). Féach Mac Aodhagáin, leis. SGG.|
|O'Hagan||numerous: mainly Ulster. Ir. Ó h-Ágáin, probably originally Ó h-Ógáin. There is also Ó h-Aodhagáin, a sept of Oriel, to add to the O'Hagans who were primarily of Tyrone and had the office of inaugurating the O'Neill as chief. IF.|
DEDs where O'Hagen and a second surname are found together