Blessed Grand Duke Demetrius of Donskoy, son of Prince John the Red and Princess Alexandra, grandson of John Kalita, was born (12) on October 20, 1350 and was raised in love with God and the Holy Church under the leadership of St. Alexy of Moscow. The saint was greatly assisted in the education of the prince by St. Sergius of Radonezh. From an early age, Dimitri, listening to his father’s stories about his glorious ancestors — Alexander Nevsky, Daniel of Moscow and other noble princes, strengthened his responsibility for his origin.
As a nine-year-old boy, after the death of his father, Demetrius went to the Horde and received permission from the khan to inherit his father's reign. The Christian piety of Saint Prince Demetrius was combined with the talent of an outstanding statesman. Dimitri fortified Moscow by surrounding the Kremlin with walls of white stone to replace the oak ones that burned during the fire, and placed the latest weapons of that time on the walls of the — cannon. Moscow was able to withstand three sieges by a huge Lithuanian army. Demetrius devoted himself to the cause of uniting the Russian lands under the leadership of the Grand Dukes of Moscow and liberating Rus' from the Mongol-Tatar yoke.
For all his deeds, the Grand Duke received the blessing of the Church. Gathering strength for a decisive battle with the hordes of Mamai, Saint Demetrius visited the monastery of the Life-Giving Trinity and told St. Sergius about his doubts due to the small number of his squads (in comparison with Mamayev’s army). The monk offered prayers to God and blessed the prince, predicting victory for his Christian army. The elder inspired the prince and his warriors by sending them two Trinity schemists — Alexander (Peresvet) and Andrei (Oslyaby) to help them. Before the battle, Saint Demetrius fervently prayed to God and addressed the soldiers, saying: «Brothers, it’s time for us to drink our cup, and let this place become a grave for us for the name of Christ...».
The battle took place on the Kulikovo Field, between the Don and Nepryadva rivers, on the day of the Nativity of the Blessed Virgin Mary, in September 1380. Before the Russians spoke out against the Tatars, the relics of the Holy Blessed Prince Alexander Nevsky were discovered in Vladimir. Dimitri Ioannovich learned of this before the battle and was fortified with invisible help from his great ancestor. The battle began with a duel between monk Alexander Peresvet, who accepted the challenge of the Tatar hero Chelubey to fight. The warriors were knocked down and fell dead.
The Grand Duke took part in the battle along with simple warriors. The prediction of St. Sergius came true: the Lord did not abandon the Russian army. Many saw Angels, the Archangel Michael, the passion-bearers Boris and Gleb, and the princely patron Demetrius of Thessalonica over the Kulikovo Field.
The entry into the battle of an ambush Russian regiment under the command of governor Dimitry Bobrok and Prince Vladimir Andreevich the Brave decided the outcome of the battle. The Tatars fled, abandoning their convoys. For this victory, Grand Duke Dimitri began to be called Donskoy. In gratitude to God and the Blessed Virgin Mary, Saint Demetrius built the Assumption Monastery on the Dubenka River and created the Church of the Nativity of the Blessed Virgin Mary on the graves of fallen soldiers.
At the same time, in the Trinity Monastery, the holy prince began a national commemoration of the killed soldiers (this is how Dimitrievskaya Parental Saturday arose). Before his death, the Grand Duke made a spiritual will, commanding his children to honor their mother —, Grand Duchess Eudokia (in monasticism Euphrosyne, canonized), and the boyars to live according to the commandments of God, affirming peace and love.
Prince Dimitri reposed himself with the Lord in 1389 and was buried in the Archangel Cathedral of the Moscow Kremlin. His canonization took place in 1988. The Russian Orthodox Church honors the memory of St. Demetrius of Donskoy on June 1 according to the new style.