His incorrupt relics were preserved and glorified by miracles. In the year 1238, during the time of the incursion of Batu upon the Russian Land, the Tatars burned the cathedral at Vladimir. In this conflagration perished Bishop Metrophanes, Great-princess Agatha, wife of Great-prince George Vsevolodovich (+ 1238), and many inhabitants of the city of Vladimir, who were locked in the cathedral church. The fire, however, did not even touch the tomb of St Gleb. Years later, in July 1410, Tatars again descended upon Vladimir. In plundering the city, they began to sack the cathedral church treasury, having murdered the door-keeper Patrick. Supposing that treasure was hidden in the saint’s tomb, they set about to break it open. Just as the Tatars touched the stone crypt of St Gleb, flames shot forth from it, and the Tatars fled the city in terror.
Through the prayers of the holy prince the city was saved from an incursion of Polish-Lithuanian plunderers in 1613.
The celebration of St Gleb was established in the year 1702, and then also a service was written to him, and somewhat later, a Life. His relics rest in the Dormition cathedral in Vladimir. In the year 1774 the south chapel of the cathedral was dedicated to him. Prince Gleb is revered as the special patron and defender of the city of Vladimir.