The Turkish army, which was spread over the country between the Danube and the Dniester, now crossed this latter stream, and, in solid battalions, four hundred thousand strong, penetrated the Ukraine. They immediately commenced the fiend-like work of reducing the whole province to a desert. The process of destruction is swift. Flames, in a few hours, will consume a city which centuries alone have reared. A squadron of cavalry will, in a few moments, trample fields of grain which have been slowly growing and ripening for months. In less than a fortnight nearly the whole of the Ukraine was a depopulated waste, the troops of the tzar being shut up in narrow fortresses. The King of Poland, apprehensive that this vast Turkish army would soon turn with all their energies of destruction upon his own territories, resolved to march, with all the forces of his kingdom, to the aid of the Russians. One hundred thousand Polish troops immediately besieged the great city of Humau, which the Turks had taken, midway between the Dnieper and the Dniester. John Sobieski, the newly-elected King of Poland, was a veteran soldier of great military renown. He placed himself at the head of other divisions of the army, and endeavored to distract the enemy and to divide their forces. At the same time, Alexis himself hastened to the theater of war that he might animate his troops by his presence. The Turks, finding themselves unable to advance any further, sullenly returned to their own country by the way of the Danube. Upon the retirement of the Turks, the Russians and the Poles began to quarrel respecting the possession of the Ukraine. Affairs were in this condition when the tzar Alexis, in all the vigor of manhood, was taken sick and died. He was then in the forty-sixth year of his age. His first wife, Maria Miloslouski, had died several years before him, leaving two sons and four daughters. His second wife, Natalia Nariskin, to whom he was married in the year 1671, still lived with her two children, a son, Peter, who was subsequently entitled the Great, as being the most illustrious monarch Russia has known, and a daughter Natalia. Alexis, notwithstanding the unpropitious promise of his youth, proved one of the wisest and best princes Russia had known for years. He was a lover of peace, and yet prosecuted war with energy when it was forced upon him. His oldest surviving son, Feodor, who was but eighteen years of age at the time of his father's death, succeeded to the crown. Feodor, following the counsel which his father gave him on his dying bed, soon took military possession of nearly all of the Ukraine. The Turks entered the country again, but were repulsed with severe loss. Apprehensive that they would speedily return, the tzar made great efforts to secure a friendly alliance with Poland, in which he succeeded by paying a large sum of money in requital for the provinces of Smolensk and Kiof which his arms had recovered.