Taken from an old out of print book titled, "The Lives of the Saints" "The Most Holy Name of Mary"
The Turks invaded the German Empire in 1683, while Mohammed IV ruled in Constantinople. A mighty Moslem army marched through Hungary and Austria, until it came in sight of Vienna. To their disgrace, it must be said that Christians had provoked the infidels to this attack. Yielding to the entreaties of his generals, Leopold I left Vienna together with the Empress. The Turkish army of 150,000 men, reinforced by 40,000 Hungarians who were in rebellion against the Emperor, laid siege to the capital from July 14th to September 12th.
Pope Innocent IX and John Sobieski, King of Poland, had entered into a league to support the Emperor against the common enemy. Therefore, as soon as Sobieski heard of the siege, he at once made ready to march to the relief of the besieged. On September 11th the Christian army took up its position on the mountains near Vienna.
On the next day Sobieski, placing himself under the patronage of the Blessed Virgin Mary, attacked the enemy and the Turks were completely routed. Vienna and Christendom were saved. In commemoration of this victory, Innocent XI instituted the feast of the Holy Name of Mary, that on it the faithful may recommend to God, through the intercession of the Blessed Virgin, the necessities of the Church and return Him thanks for His protection.
Prayer: Grant, we beseech you, almighty God, that your faithful people who rejoice in the invocation and protection of the most holy Virgin Mary, may , by her loving intercession, be delivered from all evils on earth and deserve to enter into everlasting joys in heaven. Amen.