Those tested positive for L813 are encouraged to upgrade to a Big Y-700 test during a sale period, and join the I-L813 Project. The I-L813 Haplogroup is defined by the following SNPs: L813/Z719/S436, CTS9346, CTS1345/S297/Z718, Z720, Z26348, Z26349, and FGC59332, and there are well over 300 further descended subclades of L813, the overwhelming majority of which were discovered in members’ Big Y-500/700 test results. The Median Time to Most Recent Common Ancestor for I-M253 Big Y-700 testers is 502 years, per a December 2021 FTDNA online post (I-L813 is a descendant of I-M253. Consequently, there is potential for I-L813 Big Y-700 testers to create a family haplogroup, or even branch your family further, by persuading an STR surname match to also upgrade to Big Y-700. Please see the DNA Results Y-DNA page to find your kit listed (use your browser’s Find feature) with your fellow clade-mates, and see those in the nearby groups also, what their names are, and where they’re from. This helps show you the ancestry of your family, further back in time. Also see the Background page. Welcome to L813 !!!