Hourihane, Horrigan, Hanrahan, and Horan

Joint DNA Projects
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Current Summary of Results

Last updated: August 25, 2018


There has been west Cork lore suggesting that O'Hourihanes may have come from County Clare. From that lore came our original research hypothesis that west Cork Hourihanes could have been of Dal Cais (Irish Type III) origin. So far, no Y genetic evidence has turned up to prove either a County Clare geographic origin or a Dal Cais genetic origin.

The majority of the Cork Hourihanes tested to date are Irish Type II, correlated with R1b-CTS4466 (formerly called "South Irish"). They are genetic kin to the O'Donovans, rulers of the Ui Fidgenti kingdom of Limerick. These Hourihanes are represented in project group 2. New results show Cork Hourihanes in Irish Type I, correlated with R1b-M222 ("North Irish"). There is insufficient data to even expound on it on the project website. More new research has uncovered Cork Hourihanes falling under R-L513, included in project group 4.


There is some evidence that Horgan, Horrigan, Harrigan, Hourigan, Orgain etc. share a genetic relationship. Those who do fall into an Irish Sea (Leinster/Lagin people) subclade (R1b-Z255). The Horrigans are split into two project groupings. The group 5 testers seem to share a genetic relationship, and some members of this project group show relationships within a genealogical timeframe. Overall, the relationships are somewhat remote. Group 6 is a group of Hourigans, most of whom are close relatives. They do not match the group 5 Horrigans. They may be in R-Z255 but there is too little data to know.


Our Hanrahans fall into two groups. Project group 3 members have ancestry from County Clare and fall under Irish Type III ("Dal Cais", R-L226). Other Hanrahans have ancestry from Tipperary and Westmeath. They fall under R-L513, covered in project group 4. Perhaps this is evidence of two Hanrahan septs.


Horan is most widely distributed in Ireland and we anticipate Horans to be in different haplogroups.

Some are in R-L513 (project group 4) and remotely match men named Hanrahan. One Horan fits under Irish Type I.


The project has Hourihanes, Horans and Horrigans with no meaningful genetic matches and who fall outside the main groupings. So far, they are all haplogroup R1b.

The near-identical heraldry of Hourihane, Hanrahan, and Horgan has no bearing on the true genetic origins of these surnames. There is no genetic evidence to date showing that these surname categories are closely related to each other within a genealogical timeframe.