Right-believing Demetrios Donskoy, Grand Prince of Moscow - Troparion & Kontakion
Troparion — Tone 3
In you the Russian land has found a great defender in a time of tribulation, / O vanquisher of the pagans. / At the Don you defeated the vainglorious Mamai; / having received the blessing of Saint Sergius for this undertaking; / and so, Prince Demetrios, pray to Christ God to grant us great mercy.
Kontakion — Tone 2
By your deeds, Saint Demetrios, / God preserved our country by granting you invincible power. / And now, our powerful defender, / by your holy prayers, keep your city of Moscow safe from all hostile schemes.