How all the O'Malley's are related

The diagram below shows how all the O'Malley's in the DNA Project are related to each other. It summarises the placement of all the various O'Malley groups on a single family tree. To the right is a summary of the major historical events in Ireland that our ancestors lived through and that shaped the genetic signatures of the O'Malley's today.

Click to enlarge (it takes a while to load). 
A high quality pdf version (1.1 MB) is available to download here
Update: a newer version (May 2022) is available here

There are 5 main genetic groups within the project so far. 

• Group 1 goes back to Galway in 1795. See previous post here.
• Group 2 represents the Limerick O'Malley's and consists of 6 subgroups. See here.
• Group 3 represents the Mayo O'Malley's and consists of 7 subgroups currently, many with roots in Mayo. See here and here.
• Group 4 participants probably share a common ancestor in the 1700s, possibly from Kilkenny. See here.
• Group 5 is another Galway group (with Kilmilkin origins). This group was previously associated with the surname Joyce. See this article here.

The Group 2 O'Malley's all sit beneath the branch characterised by L226, which is the marker for the Dalcassian group of surnames. They would therefore be related to Brian Boru, first High King of Ireland (941-1014). These subgroups would all share a common ancestor about 1500 years ago. These O'Malley's can be traced back to the 1100's in Limerick and arose completely independently from the Mayo O'Malley's. See previous articles here and here. 

Note that the horizontal green line indicates the time when surnames were introduced into Ireland, and that all subgroups are connected to common ancestors above this line (i.e. pre-surnames). The single exception is Group 2a and 2b, which may in fact be related by a common ancestor (DC362) who lived after surnames were introduced. As we get more data, it should be possible to refine the age estimate for the common ancestor of these two subgroups.

The Group 3 subgroups all sit beneath the branch characterised by the SNP marker M222 and therefore are related to Niall of the Nine Hostages (NOTNH). This is not surprising given that the Mayo O'Malley's are recorded as being descendants of Niall's brother Brian. (1) These subgroups would all share a common ancestor about 2100 years ago.

The Groups 2, 3 and 4 would share a common ancestor (who carried the marker DF13) about 4100 years ago. Group 5 would share a common ancestor (M785) with Groups 2, 3 and 4 about 23,000 years ago. And the common ancestor they all share with Group 1 (PF3495) would have lived about 47,000 years ago.

Not included in this diagram are the 11 O'Malley men who currently remain in the Ungrouped section of the project. These are people who currently do not have a match within the project, but as more people join, many of these will form new groups, causing the project to continually expand.

In the next article we will look at why there are so many different genetic signatures within the O'Malley DNA Project ... and you may find some of the possible reasons rather surprising ...

Maurice Gleeson

April 2022

Sources & Links

1) O Hart, J (1892) Irish Pedigrees: or the Origin and Stem of the Irish Nation. Available online here.

Update 26th April 2022

Following the availability of new Y-DNA results, the chart has now been updated to include the following:

• a new SNP marker for Group 3a1
• a completely new Group 3g for the Kilmilkin O'Malley's
• revised possible origins for Groups 4 and 5
• some minor refinements following feedback from project members

The revised chart is below and available for download here.

(click to enlarge)