The Oster volost of the Pereyaslavl land

In the 12th century Gorodets Ostersky (1098) became a staging ground for Kievand Pereyaslavl’ conquests; however, no information on its vicinity was available. The 1773map contains an outline of a long fortification line located north of the city whose purposeis now lost. In the 10th-13th cc. it, probably, performed the function of a borderlinewith the Chernigov lands, with marshes extending beyond it. Its curve surroundedthe northern vicinity of Gorodets which had an area of 1,300 sq. km. Gorodets ownedthe town of Nosov and the fortified settlement of Krekhaev located south of the city.They were linked to a line of sites located some 10-23 km away from the Oster River;the area of this zone is 1,300 sq. km. The Pereyaslavl’ lands were further to the south;their boundary runs almost parallel to the Oster border and is 15-18 km away. Giventhese data, the borders of the Oster Volost can be realistically traced down. The total areaof the volost was 2,600 sq. km, which is similar to the core of the Pereyaslavl’ principalityafter the Kiev ’belt’ was appropriated from it in accordance with the Prince Yaroslav’division’ (2,800 sq. km). Therefore, Yury Dolgoruky and the Olgovits from Chernigovhad weighty reasons to wage long wars to win such vast lands.