DEMETRIUS DONSKOI (1350-1389), grand duke of Vladimir and Moscow, son of the grand duke Ivan Ivanovich by his second consort Aleksandra, was placed on the grand-ducal throne of Vladimir by the Tatar khan in 1362, and married the princess Eudoxia of Nizhniy Novgorod in 1364. It was now that Moscow 1 Of the Don. was first fortified by a strong wall, or kreml (citadel), and the grand duke began " to bring all the other princes under his will." Michael, prince of Tver, appealed however for help to Olgierd, grand duke of Lithuania, who appeared before Moscow with his army and compelled Demetrius to make restitution to' the prince of Tver (1369). The war between Tver and Vladimir continued intermittently for some years, and both the Tatars and the Lithuanians took an active part in it. Demetrius was generally successful in what was really a contention for the supremacy. In 1371 he won over the khan by a personal visit to the Horde, add in 1372 he defeated the Lithuanians at Lyubutsk. Demetrius then formed a league of all the Russian princes against the Tatars and in 1380 encountered them on the plain of Kulikovo, between the rivers Nepryadvaya and Don, where he completely routed them, the grand khan Mamai perishing in his flight from the field. But now Toktamish, the deputy of Tamerlane, suddenly appeared in the Horde and organized a punitive expedition against Demetrius. Moscow was taken by treachery, and the Russian lands were again subdued by the Tatars (1381). Nevertheless, while compelled to submit to the Horde, Demetrius maintained his hegemony over Tver, Novgorod and the other recalcitrant Russian principalities, and even held his own against the Lithuanian grand dukes, so that by his last testament he was able to leave not only his ancestral possessions but his grand-dukedom also to his son Basil. Demetrius was one of the greatest of the north Russian grand dukes. He was not merely a cautious and tactful statesman, but also a valiant and capable captain, in striking contrast to most of the princes of his house.
See Sergyei Solovev, History of Russia (Rus.), vols. i.-ii. (St Petersburg, 1857), etc. ; Nikolai Savelev, Demetrius Ivanovich Donskoi (Rus.), (Moscow, 1837). (R. N. B.)
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)