R1a-M12205 (formerly R1a-Y2619) Ashkenazi Levites

About R1a-M12205 (formerly R1a-Y2619) Ashkenazi Levites

This website is devoted to the R1a-M12205 Ashkenazi Levite Y-DNA cluster, known as the R1a-Y2619 Ashkenazi Levite cluster until October 2026 and previously referred to as the R1a1a Ashkenazi Levite cluster.  

The  early literature often used the term R1a1a Ashkenazi Levites, and the literature from about 2017 through 2026 typically used the term R1a-Y2619 Ashkenazi Levite; upon identification in 2026 of a level downstream from R1a-Y2619 given the name R1a-M12205, the cluster should now properly be known as R1a-M12205 Ashkenazi Levites. Due to the longstanding use of the term R1a-Y2619 Ashkenazi Levites on this website and elsewhere, this website will continue to use the term R1a-Y2619 Ashkenazi Levites as well as the term R1a-Y12205 Ashkenazi Levites to refer to this cluster.

According to a 2003 study, about 52% of Ashkenazi men with a tradition of Levite descent belong to the R1a haplogroup. That haplogroup is less common  among Ashkenazim without a tradition of Levite descent (and R1a-M12205 men without a tradition of Levite descent are often able to determine from genealogical records or tombstones that their direct male line is in fact Levite). The haplogroup is found only rarely among Sephardim (both Levites and non-Levites). 

Men belonging to this R1a cluster of Ashkenazi men have over time been referred to as (1) R1a1a Ashkenazi Levites, (2) R1a-Y2619 Ashkenazi Levites, and (3) R1a-M12205 Ashkenazi Levites. (Y2619 and M12205 are a single-nucleotide polymorphisms ("SNPs") that are shared by all R1a1a Ashkenazi Levites. Up until October 2026, Y2619 was believed to be found only in R1a1a Ashkenazi Levites. In October 2026, however, Y2619 was discovered in a Pamiri man from Tajikistan, splitting the R1a-Y2619 level. As of October 2026, M12205 is one of 14 SNPs downstream from the T1a-Y2619 level that is shared by all R1a1a Ashkenazi Levites but has not been found in anyone who is not an R1a1a Ashkenazi Levite. 

Dr. Doron Behar’s November 2017 paper on R1a-Y2619 Ashkenazi Levites, D. Behar et al., The genetic variation in the R1a clade among the Ashkenazi Levites’ Y chromosome, SREP-17-37687 (2017), of which the author of this website is a co-author, sets forth the information known as of 2017 concerning the R1a-Y2619 Ashkenazi Levite cluster. This website posts a summary of that paper. 

In short, all R1a-Y2619 Ashkenazi Levites (now R1a-M12205 Ashkenazi Levites) are descended on their direct male lines from a single man (referred to on this website as the R1a-Y2619 Ashkenazi Levite progenitor or the R1a-M12205 Ashkenazi Levite progenitor) who lived about 1,743 years ago, according to the 2017 Behar paper, or about 1,200 years ago, according to the YFull tree as of July 2021. About 7.9% of the Ashkenazi population - about 300,000 men living today - are descended from the R1a-M12205 Ashkenazi Levite progenitor on their direct male lines. R1a-M12205 is one of the largest Y-DNA clusters - if not the largest Y-DNA cluster - among Ashkenazi Jews.

The R1a-M12205 Ashkenazi Levite progenitor was not only Jewish but also Levite, as is evidenced by the fact that men on all four branches of R1a-M12205 predominantly have traditions of not only Jewish but also Levite descent on their direct male lines. 

The R1a-M12205 Ashkenazi Levite progenitor was very likely Ashkenazi. as is evidenced by the fact that men on all four R1a-M12205 Ashkenazi branches are predominantly of Ashkenazi origins. While there are some R1a-M12205 Ashkenazi Levite with most distant known ancestry in non-Ashkenazi regions, those men's Y-DNA results put them into largely Ashkenazi clusters. 

The branch immediately upstream from the R1a-Y2619 branch is known as R1a-M582 in the scientific literature and as R1a-CTS6 on the FTDNA and YFull trees. The R1a-M582/CTS6 progenitor - the direct male ancestor of the R1a-Y2619 line - lived in the area of Iran as of about 3,143 years ago, according to the 2017 Behar paper, or about 2,800 years ago, according to the YFull tree as of July 2021. The geographic origins of the R1a-M582/CTS6 line is demonstrated by the fact that men who belong to R1a-M582/CTS6 clusters other than the R1a-Y2619 cluster are found larbely in Iran and adjacent regions. 

Up until October 2026, according to FTDNA's Discover Tool's haplogroup reports for R-CTS6 and R-Y2619 there was a bottleneck in the R1a-Y2619 line between the time that the R1a-Y2619 cluster was formed in about 1300 BCE and the time that the R1a-Y2619 cluster began branching in about 750 CE.

In October 2026, the R1a-Y2619 line was split by the discovery of a Pamiri man from Tajikistan who shared six of the 20 SNPs that had previously defined the R1a-Y2619 level. Because that man was positive for Y2619, it became necessary to use a new SNP to identify the Ashkenazi Levites within R1a-Y2619. Family Tree DNA chose the SNP R1a-M12205 to identify that cluster.

As of October 2026, FTDNA's Discover Tool's Haplogroup Reports for R-Y2619 and R-M12205 estimated that the R1a-Y2619 progenitor lived in about 600 BCE, while the R1a-M12205 progenitor lived in about 750 CE - a bottleneck of about 1,350 years. The new evidence suggests that the R1a-M12205 line was likely in the area of Iran as of about 600 BCE, and that the line was not yet part of the Jewish population at that time. The current Y-DNA evidence does not allow determinations as to when the R1a-M12205 line (1) moved from the area of Iran to Europe or (2) became part of the Jewish population.

Perhaps 40% of Ashkenazi Jews with a Levite tradition are not R1a-M12205 Ashkenazi Levites. If you have information or links concerning Levites who are not R1a-M12205 Ashkenazi Levites, please e-mail us with such information or links for possible inclusion on this website.

About the Website

This website contains a detailed analysis of the interrelationships among individual R1a-M12205 Ashkenazi Levites based upon SNP and STR testing, as well as discussions of the historical background of R1a-M12205 Ashkenazi Levites and theories concerning the origins of R1a-M12205 Ashkenazi Levites. The website presents some genealogical information concerning Levites, focusing on the Horowitz rabbinical family, which comprises a significant cluster of R1a-M12205 Ashkenazi Levites. The website also provides background on Y-DNA testing and analysis, as well as generally applicable advice for interpreting and evaluating Y-DNA results.

The Y-DNA analysis set forth on this website applies to all men who belong to the R1a-M12205 Ashkenazi Levite subclade, regardless of whether they have a tradition of Levite descent.  All men belonging to this subclade are descended from Levite men on their direct male line, even if such men lack a tradition of Levite - or Jewish - descent. A significant number of R1a-M12205 men have discovered their Levite - or Jewish - ancestry only after receiving Y-DNA test results.

This website started as a Yahoo group created in January 2013 to share a sortable spreadsheet of Y-DNA results for what were then known as R1a1a Ashkenazi Levites, along with a methodology for analyzing the results to identify relatively close matches based upon shared patterns of Short Tandem Repeat ("STR") marker values. As of that time, the spreadsheet included STR marker values for about 260 R1a1a Ashkenazi Levites who had tested through Family Tree DNA ("FTDNA") to at least 37 markers. (The results were compiled from various public sources, including FTDNA project pages, and from matches who provided their results for inclusion in the analyses.) 

Throughout 2013, additional analyses were posted as attachments on the Yahoo group website.  On December 14, 2013, the content of the Yahoo group website was placed on this website, www.levitedna.org. 

Starting in mid-2014, the website provided a SNP-based tree for R1a-Y2619 Ashkenazi Levites and their closest matches.  As of that time, the tree included the results for five R1a-Y2619 Ashkenazi Levites who had done full Y-DNA testing - two men who had tested through FTDNA's newly introduced Big Y test, two men who had tested through Full Genomes Corporation's recently introduced full Y-DNA testing, and one man who had been tested for scientific papers.

As discussed in detail on the What's New page, the website has continued to be updated over time, both by adding new results for R1a-Y2619 Ashkenazi Levites (now R1a-M12205 Ashkenazi Levites) as they have been received and by discussing new research - most significantly, the 2013 Rootsi & Behar paper and the 2017 Behar paper on R1a-Y2619 Ashkenazi Levites, as well as the 2016 test results for the Pamiri man splitting the R1a-Y2619 level. 

With the arrival of more results of full Y-DNA testing and additional analyses, it became apparent that the R1a-Y2619 Ashkenazi Levite cluster (now the R1a-M12205 Ashkenazi Levite cluster) was older and had more branching than had appeared in 2013 to be the case based upon the initially received results. Thus, while the earliest version of this website had concluded that a large proportion of R1a1a Ashkenazi Levites were descended from or closely related to the founder of the Horowitz rabbinical family, who lived in the late 15th century, it is now clear that the relationship of most R1a-M12205 Ashkenazi Levites to the Horowitzes is more distant, often going back to 750 CE.

The broader discussions and analyses on the website have been updated periodically, with significant revisions in July 2021 and updates in October 2026. However, for historical purposes, the website posts some discussions and analyses that have been superseded or supplemented over time.  (In most instances, such discussions and analyses are flagged as having been included for historical reasons.)

The website is regularly updated to include newly received STR and SNP results for R1a-M12205 Ashkenazi Levites. The most frequent updated are to the pages with the SNP tree and the schematic SNP tree for R1a-M12205 Ashkenazi Levites, and the subpages to that page concerning FTDNA's tree and YFull's tree for that cluster. As of October 2026, this website posted an SNP-based tree (in schematic form and linked at the bottom of this page in complete form) for more than 400 R1a-M12205 Ashkenazi Levites who had done full Y-DNA testing. The What's New page identifies new and recently revised pages.

Because SNP testing has supplanted STR testing, the following pages are no longer being regularly updated: (1) the R1a-M12205 Ashkenazi Levite Sortable Spreadsheet, the Y-Utility spreadsheet with STR marker values, and the Steps to Matches spreadsheet for use with the Sortable Spreadsheet; and (2) various STR-based, computer-generated trees for R1a-Y2619 Ashkenazi Levites. As of July 2023, the website posted a spreadsheet (linked at the bottom of this page) with STR marker values for about 840 R1a-Y2619 Ashkenazi Levites who had tested through FTDNA to at least 37 markers; this spreadsheet is not being updated online. 

This website complements a Google group (formerly a Yahoo group) and a Facebook group for people who are interested in R1a-Y2619 Ashkenazi Levites (now R1a-M12205 Ashkenazi Letives). Both groups have been created to facilitate discussion and to post announcements concerning updates to this website.

Information concerning the Y-DNA ancestral lines of Ashkenazi Jews and Y-DNA and mtDNA haplogroup frequencies for Ashkenazi Jews, previously posted on this website, is now posted on a separate website.

Comments or updated information may be sent to jeffwexler@ca.rr.com.

Acknowledgements

Thanks to Meir Garbarz Gover and Ben Weinstock for their comments, suggestions, assistance, and insight with regard to the issues discussed on this website, to Jim Wald for providing artwork and photographs posted throughout this website, to Michał Milewski and A.J. Levin for their general assistance and insight, and to Dr. Doron Behar for the opportunity to assist in his research.