The ancient construction was found on the area of old fortress near Archangel Mikhail Cathedral built in the 17th century.  

Recently experts have confirmed that the church is really about 800 years old. However, little has remained of it – only a small altar part, the so-called apsis. It is surprising that the church was made not of wood, but of very expensive Byzantine flat burned brick.

“This fact denotes great importance of Karachev town. Finds of such a level are discovered once in hundred years. Two similar churches - in Vshchizh and Trubchevsk – were found in the 19th and the mid 20th centuries. During Kievan Rus’ these were large cities, princely residences. All churches there were built on money of princes” – explained doctor of history, Bryansk State University professor Evgeny Shinakov.

Karachev, he says, was a small town. There has remained no annalistic data showing that it in the 12th century, during the pre-Mongolian period, it was a princely residence. But after this find experts have started telling that it was possibly a capital city.    

- It is not ruled out that in Karachev there was a residence of princes of the Novgorod-Seversk branch of the Chernigov dynasty. Probably, it was even that of Svyatoslav Olgovich, among whose descendants there was Prince Roman Bryansky as well.

Sources: http://www.kp.ru