This website is devoted to the R1a1a Ashkenazi Levite Y-DNA subclade.
According to a 2003 study, about 52% of Ashkenazi men with a tradition of Levite descent belong to the R1a haplogroup. That haplogroup is relatively rare among Ashkenazim without a tradition of Levite descent and still more uncommon among Sephardim (both Levites and non-Levites). Men belonging to this R1a cluster of Ashkenazi men have become known as R1a1a Ashkenazi Levites or, more recently, as R1a-CTS6 (CTS6 is a single-nucleotide polymorphism ("SNP") that is currently believed to be shared by all R1a1a Ashkenazi Levites.)
The DNA analysis set forth on this website applies to all men who belong to the R1a1a Ashkenazi Levite subclade, regardless of whether they have a tradition of Levite descent. It appears probable that 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.
We have determined that: (1) known descendants of the Horowitz Levitical rabbinical family of Prague are R1a1a Ashkenazi Levites; and (2) a substantial number of the R1a1a Ashkenazi Levites who have tested to at least 37 Short Tandem Repeat ("STR") markers appear to share a common ancestor who lived in or about the 15th century. We believe that this common ancestor – who may be the direct male ancestor of as many as 1% of Ashkenazim living today – may be the founder of the Horowitz rabbinical family, Rabbi Isaiah ben Moshe Asher Halevi Horowitz (@1440 – 1515). Most of the Horowitz men who have tested STR markers to date appear to be descended from the line of Isaiah’s great grandson Pinchas Halevi Horowitz (1535-1618), but we have test results for groups of men who apparently descend from Isaiah through other lines (presumably including the line of Isaiah’s grandson the Shelah, Rabbi Isaiah Halevi Horowitz (1568-1627)).
This website contains a detailed analysis of the marker values of and interrelationships among individual R1a1a Ashkenazi Levites, as well as discussions of the historical background of R1a1a Ashkenazi Levites and theories concerning the origins of R1a1a Ashkenazi Levites. The website presents some genealogical information concerning Levites, focusing on the Horowitz rabbinical family; we hope to add more information. The website also provides background on Y-DNA testing and analysis, and generally applicable advice for interpreting and evaluating Y-DNA results.
This website complements a Yahoo group that we have formed to allow people who are interested in R1a1a Ashkenazi Levites may review documents and engage in discussions. We have also created a Facebook group to facilitate discussion and to post announcements concerning updates to this website.
About 50% of Ashkenazi Jews with a Levite tradition are not R1a1a Ashkenazi Levites. If you have information or links concerning Levites who are not R1a1a Ashkenazi Levites, please e-mail us with such information or links for possible inclusion on this website.
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, and to Michał Milewski and A.J. Levin for their general assistance and insight.