Then, the situation of this Kiev country was such as to expose it to continuous invasion on the part of the nomadic warlike tribes which infested the steppes of the Ukraine. But the nation managed to hold them in check during this weary term of warfare. When, however, the hosts of the Mongol potentate, Djingis Khan, appeared in the Pontian steppes, the resources of Kiev and Halich were no longer equal to the pressure. In the three days’ battle on the Kalka (1224) their army was annihilated, and in 1240 the city of Kiev was razed to the ground. The principality (later kingdom) of Halich survived it by almost a century, but could not withstand the continued aggressions of the Tatars on the one side and of the Poles and Lithuanians on the other; in 1340 it was incorporated with Poland by right of succession, and thus ended the first national organization of the Ukrainian People. All the Ukraine, excepting the forest regions in the northwest, had been completely devastated. The Polish-Lithuanian state treated the Ukraine as [181]conquered territory. Being now dissenters in the midst of a Catholic state, the Ukrainian nobles were limited in their prerogatives, and deserted their faith and their nationality, in order to have a share in the golden freedom of Poland. The burgher class was tyrannized (as was the practice all over Poland); the peasant became a serf. The splendid task of an ecclesiastical union with Rome was solved (Florence, 1439; Brest 1596) in an unsatisfactory manner and bore little fruit at the time. Every Ukrainian was made to feel the iron hand of the Polish government, and their dissatisfaction expressed itself in numerous rebellions. And yet the Polish-Lithuanian State was far too weak to protect the Ukraine against the onslaughts of the Tatars. Every year these hordes of riders sallied forth from the Crimea, pushing their invasions even as far as Galicia and Volhynia, devastating the country and depopulating it by seizures of slaves, conducted according to a systematic plan. The victims of this slave trade filled the markets of the Orient for centuries. It was inevitable that this sorely-tried nation should take steps to defend itself. And its efforts were successful in that they led to the formation of a new independent state, but unsuccessful in that they exhausted its resources and later had a tragical outcome. The constant state of warfare on the Tatar border forced the Ukrainian population in those parts to adopt a policy of continual “Preparedness.” These fighting people of the marshes led a precarious life, but they had access to the virgin lands of the borders with all their natural treasures, and the exploiting Polish officials did not dare venture forth into these dangerous districts. These armed farmers, hunters and fishermen led an independent life and called themselves Cossacks, i.e., “free warriors.”