The book of the Russian historian Pyotr Vasilyevich Golubovsky (1857-1907) "The History of the Seversky Land," written on the basis of a thorough analysis of annals and archaeological materials, is one of the most thorough studies on the history of this region. The work is dedicated to the history of the northerners, an East Slavic tribe that has long lived along the banks of the Desna, Sejm and Sula rivers. The author speaks of northerner colonization, attracting evidence of annals, Arab and Greek sources, archaeological data.