Encouraged by this success, the grand prince made arrangements for other exploits.  A border warfare ensued, which was continued for several years with alternating success and with great ferocity.  Neither party spared age or sex, and cities and villages were indiscriminately committed to the flames.  Russia was soon alarmed by the rumor that Mamai, a Tartar chieftain, was approaching the frontiers of Russia with one of the largest armies the Mogols had ever raised.  This intelligence roused the Russians to the highest pitch of energy to meet their foes in a decisive battle.  An immense force was soon assembled at Moscow from all parts of the kingdom.  After having completed all his arrangements, Dmitri, with his chief captains, repaired to the church of the Trinity to receive the benediction of the metropolitan bishop.

“You will triumph,” said the venerable ecclesiastic, “but only after terrible carnage.  You will vanquish the enemy, but your laurels will be sprinkled with the blood of a vast number of Christian heroes.”

The troops, accompanied by ecclesiastics who bore the banners of the cross, passed out at the gate of the Kremlin.  As the majestic host defiled from the city, the grand prince passed the hours in the church of Saint Michael, kneeling upon the tomb of his ancestors, fervently imploring the blessing of Heaven.  Animated by the strength which prayer ever gives, he embraced his wife, saying, “God will be our defender,” and then, mounting his horse, placed himself at the head of his army.  It was a beautiful summer’s day, calm, serene and cloudless, and the whole army were sanguine in the hope that God would smile upon their enterprise.  Marching nearly south, along the valley of the Moskwa, they reached, in a few days, the large city of Kolomna, a hundred miles distant, on the banks of the Oka.  Here they were joined by several confederate princes, with their contingents of troops, swelling the army to one hundred and fifty thousand men.  Seventy-five thousand of these were cavalry, superbly mounted.  Never had Russia, even in her days of greatest splendor, witnessed a more magnificent array.

Mamai, the Tartar khan, had assembled the horde, in numbers which he deemed overwhelming, on the waters of the Don.  Resolved not to await the irruption of the foe, on the 20th of August, Dmitri, with his army, crossed the Oka, and pressed forward towards the valley of the Don.  They reached this stream on the 6th of September.  Soon detachments of the advanced guards of the two armies met, and several skirmishes ensued.  Dmitri assembled his generals in solemn conclave, and saying to them, “The hour of God’s judgment has sounded,” gave minute directions for the conflict.  Aided by a dense fog, which concealed their operations from the view of the enemy, the army crossed the Don, the cavalry fording the stream, while the infantry passed over by a hastily-constructed bridge.  Dmitri deployed his columns in battle array upon the vast plain of Koulikof.  A mound of earth was thrown up, that Dmitri, upon its summit, might overlook the whole plain.