Can you specify where this info comes from and where the base material originates?
Found one excerpt on Khazars here:
Another of Schechter's early discoveries was the remains of an extensive literary epistle concerning the kingdom of the *Khazars. The ruler of this Caspian kingdom, and along with him many of his subjects, accepted Judaism before the ninth century. Some correspondence between the Khazar king Joseph and Ḥisdai ibn Shaprut had been published at the end of the 16th century and much later (in 1879) by Harkavy who used material brought from Cairo to Russia; the Cambridge document considerably increased the knowledge of the conversion and of subsequent Khazar history, and supplied many useful geographical details as well. In recent years still another Cambridge Genizah manuscript pertaining to the Khazars was discovered by N. Golb.
The source is (((jstor))), OP is a jew, he does this frequently. https://pic8.co/sh/w02XF8.png https://pic8.co/sh/qRCCQp.png
(post is archived)