MOSCOW—A Russian archaeologist believes he has found the lost capital of the Khazars, an ancient Turkic people whose rulers adopted Judaism over a thousand years ago, the AP reports.

Following a nine-year excavation near the Caspian Sea, Professor Dmitry Vasilyev, of Astrakhan State University, has reported the discovery of the foundations of a triangular brick fortress, alongside modest yurt-like dwellings, which he believes to be part of Itil, the Khazar capital.

The Khazars were an tribe that roamed the steppes from Northern China to the Black Sea and between the 7th and 10th centuries conquered huge areas in what is now southern Russia, Ukraine, the Caucasus Mountains, and Central Asia.

Itil sat at a major junction of the Silk Road, which "helped Khazars amass giant profits," said Kevin Brook, the author of The Jews of Khazaria.

Sometime in the the 8th or 9th century Khazar's ruling elites converted to Judaism; scholars believe that the decision was likely taken so that they could remain independent of nearby Christian and Muslim states. Vasilyev said the limited number of Jewish religious artifacts discovered at other Khazar sites suggests that ordinary Khazars preferred traditional beliefs such as shamanism or Islam. The Khazars withstood the Arab advance, but fell to the Russians in the late 10th century.

"In many ways, Russia is a successor of the Khazar state," Vasilyev said.

But some were skeptical of his findings. Simon Kraiz, of Haifa University, said, "If they found a few buildings, or remains of buildings, that's interesting but does not make a big difference." He added, "If they found Khazar writings, that would be very important."

Vasilyev said that no Jewish artifacts have been found at the site. He also said that in general, most of what is known about the Khazars comes from the writings of other cultures.