erroneously, to the Severians (or Siverians) - a former Eastern Slavic tribe
Besides the above works and a commentary against various sects of Monophysites (Severians, Theodosians, Cainites and Acephali) he left eleven discourses in defence of Pope Leo I and the Council of Chalcedon, also a work against the Agnoetae, submitted by him before publication to Pope Gregory I, who after some observations authorized it unchanged.
The region received its name after the Severians, an East Slavic tribe which inhabited the territory in the late 1st millennium A.D. Their main settlements included the present-day cities of Novhorod-Siverskyi, Chernihiv (Chernigov), Putyvl (Putivl), Hlukhiv (Glukhov), Liubech, Kursk, Rylsk, Starodub, Trubchevsk, Sevsk, Bryansk, and Belgorod.