Oril

The Oril winds west through the forest-steppe to the Dnipro, its floodplain forming a natural boundary on the northern edge of the Zaporozhian lands. In the 1730s the Russian Empire built the Ukrainian Line along the Oril and other rivers, combining forts and earthworks against raids from the steppe. Construction demanded substantial labour, while the line helped draw settlers to the surrounding country. Its military importance waned as the frontier moved south later in the century.