The celebration in honor of the Pochaev Icon of the Mother of God on July 23 was established in memory of the deliverance of the Dormition Lavra monastery from a Turkish siege on July 20-23, 1675.
In the summer of 1675 during the Zbarazhsk War with the Turks, in the reign of the Polish King Jan Sobesski (1674-1696), regiments composed of Tatars under the command of Khan Nurredin via Vishnevets fell upon the Pochaev monastery, surrounding it on three sides. The weak monastery walls and its stone buildings did not offer much defense against a siege. The igumen Joseph Dobromirsky urged the brethren and laypeople to pray to their heavenly intercessors: the Most Holy Theotokos and St Job of Pochaev (October 28).
The monks and the laypeople prayed fervently, prostrating themselves before the wonderworking icon of the Mother of God and the reliquary with the relics of St Job. At sunrise on the morning of July 23, as the Tatars were planning an assault on the monastery, the igumen ordered an Akathist to the Theotokos to be sung. At the opening words, “O Queen of the Heavenly Hosts,” the Most Holy Theotokos suddenly appeared over the church, in “an unfurled gleaming-white maphorion,” with angels holding unsheathed swords. St Job stood beside the Mother of God, bowing to Her and beseeching Her to defend the monastery.
The Tatars believed the heavenly army was a vision, and in confusion they began to shoot arrows at the Most Holy Theotokos and St Job, but the arrows fell backwards and wounded those who shot them. Terror seized the enemy. In a flight of panic and without looking, they trampled upon and killed each other. The defenders of the monastery attempted pursuit and took many prisoners. Some of the prisoners afterwards accepted the Christian Faith and remained at the monastery thereafter.