Слово о полку Игореве
The Trubetsk (Troubchevsk) town was found in the era of vikings. The official date of town foundation is 975. It was referred to in the Old East Slavic poem "The Tale of Igor's Campaign" where, among others, Vsevolod Svyatoslavich, the Prince of Trubetsk and of Kursk, was glorified. In 1185 the Trubetsk army fought against Cumans.