E-Y6923 is a new SNP that has been discovered that represents a sub-branch of L791. The common ancestor of Y6923 was most likely a Jewish man who lived sometime around 400 CE. Y6923's two major branches are Y6938 (or Y6940), with a common ancestor who lived around 700 CE, and the more recently discovered Y102667, with a common ancestor who lived around 400 CE. If you take a look at the tree on the results page, SNPs below Y6923 have been discovered and these SNPs represent sub-branches of Y6923 whose common paternal ancestors lived as recently as 1100 to 1700 CE. The important thing to understand as a member of the E-Y6923 haplogroup is that you fall somewhere on this tree under Y6923, and together we might be able to figure out who the men who are the common ancestors of these sub-branches were, as well as when, where, and how they might have lived.