Empire. East of the Dnieper River a desolate steppe stretched to the Sea of Azov, where lack of water made early settlement precarious. Being near the Muravsky Trail exposed it to frequent Crimean–Nogai slave raids and plundering by Tatar tribes, preventing permanent settlement and keeping it sparsely populated, or even entirely uninhabited, under Tatar rule. Hence it was known as the Wild Fields or the 'Deserted Plains' (Campi Deserti in Latin). Cossack period In this region of Eurasian steppes, the Cossacks emerged as a distinct people in the late fifteenth and early sixteenth centuries. Below the Dnieper Rapids were the Zaporozhian Cossacks, freebooters organized into small, loosely-knit, and highly mobile groups who were both livestock farmers and nomads. The Cossacks would regularly penetrate the steppe to fish and hunt, as well as for migratory farming and to herd livestock. Their independence from governmental and landowner authority attracted to join them many peasants and serfs fleeing the Polish–Lithuanian Commonwealth and Grand Duchy of Moscow. The Treaty of Constantinople in 1700 further isolated the region, as it stipulated that there should be no settlements or fortifications on the coast of the Azov Sea to the mouth of the Mius River. In 1709, in response to a Cossack alliance with Sweden against Russia, Tsar Peter the Great ordered the liquidation of the Zaporozhian Sich, and their complete and permanent expulsion from the area. In 1733, Russia was preparing for a new military campaign against the Ottoman Empire and therefore allowed the return of the Zaporozhians, although the territory officially belonged to Turkey. Under the Agreement of Lubny of 1734, the Zaporozhians regained all their former lands. In return, they were forced to serve in the Russian army during wartime. They were also permitted to build a new stockade on the Dnieper River called New Sich, though the terms prohibited them from erecting fortifications. These terms allowed only for living quarters, in Ukrainian called kureni. Upon their return, the Zaporozhian population in these lands was extremely sparse, and in an effort to establish a measure of control, they introduced a structure of districts or palankas. The nearest district to modern Mariupol was the Kalmius District, but its border did not extend to the mouth of the Kalmius River, although this area had been part of its migratory territory. After 1736, the Zaporozhian Cossacks and the Don Cossacks (whose capital was at nearby Novoazovsk) came