As per the Lepanto Institute, "In 1571, at the famous Battle of Lepanto, recourse to the Rosary saved the Church against a powerful force. Soldiers and sailors still had to rely upon their wits, strength and blood in the fight, but it was Our Lady of the Rosary who ultimately brought the victory."
"In a.d. 622, Mohammed set out from Medina to conquer the whole Christian world for Allah by force of arms. Within a hundred years, his successors had occupied and pillaged every Christian capital of the Middle East, from Antioch through North Africa (home of Saint Augustine) and Spain. All that remained outside Allah's reign was the northern arc from Southern France to Constantinople.... A long line of great warrior sultans sponsored Turkish advances in shipbuilding, gunnery, military organization, and training. By the mid 1550s they had slowly conceived of a long-term offensive, a pincers movement first by sea and then by land, to conquer the whole northern shore of the Mediterranean. Their ultimate aim was to take all Italy; then all Europe. First, in 1565, they launched a massive sea attack on the crossroads of the Mediterranean, the strategically placed island of Malta. They were repelled after an epic siege (which in itself is one of history's great stories). A later northern pincers movement by land was aimed at an attack up through the Balkans, for the conquest of Budapest, and then in a northeast arc into Slovakia and Poland. In this way, the Muslim forces would essentially encircle Italy from the north. The capture of Vienna — and thus the cutting off of Italy, for easy conquest — was the prize most sought. Because by 1540 the Reformation had begun separating the Christian nations of the north from Rome, the sultans soon recognized that the Christian world would no longer fight as one. The next hundred years or so would be the most fruitful time since 632 to fulfill the destiny of Islam in Europe....
"The Knights of Malta, the premier sea warriors of the time, offered their small but highly skilled fleet in support of the pope's appeal ….an enormous Muslim fleet, nearly 100 ships larger than their own, was sailing near to land toward the Gulf of Lepanto....
In four hours the battle was over....As news of the great victory of October 7 reached shore, church bells rang all over the cities and countryside of Europe. For months, Pius V had urged Catholics to say the daily rosary on behalf of the morale and good fortune of the Christian forces and, above all, for a successful outcome to the highly risky preemptive strike against the Turkish fleets. Thereafter, he declared that October 7 would be celebrated as the Feast of 'Mary, Queen of Victory.' A later Pope added the title 'Queen of the Most Holy Rosary' in honor of the laity's favorite form of prayer....
"King Sobieski of Poland had drawn the privilege of advancing on the right flank, through the heart of the Vienna Wood....Late on September 11, just as his men were making their initial contact with the Turkish outposts, and the final battle began to be joined, the king formed a resolution to attack on the morrow as swiftly and with as much surprise as possible....once again, this time by land, the Muslims had attempted to fulfill the Prophet's command to spread Islam to all corners of the world decisively, with force....After September 11-12, 1683, that power kept receding, on into modern times. Still, it should surprise no one that the date chosen to bring the new resurgence of modern Muslim ambition to the whole world's attention was also September 11, 318 years after 1683" (National Review Online, 10/7/14). October 7 "is the memorial of Our Lady of the Most Holy Rosary, a feast instituted by Pope Saint Pius V in commemoration of the great victory... when the Christian fleet led by Don Juan of Austria crushed the invading, and seemingly invincible, navy of the Ottoman Turks"
(Catholic Insight, 10/7/22).