For historians, it is one of the eighteen most important battles in world history; for Christian Europe, however, it is a battle whose importance can only be compared to the victories at Lepanto (1571) and Vienna (1683), which saved our continent from the Muslim invasion at the time. This year, on August 15, we celebrate the 106th anniversary of the Battle of Warsaw, which has gone down in history as the “Miracle on the Vistula”: the victory of the Polish army that saved Europe from the invasion of Communist Russia.

For Poland, these were the years of regained independence. Following the three partitions that occurred between 1772 and 1795 at the hands of three powerful neighboring empires—Russian, Prussian, and Austro-Hungarian—Poland disappeared from the map of Europe for more than a century. The country regained national sovereignty on November 18, 1918, but the independence recovered after the First World War was immediately threatened, still from the East, but this time by a Russia that was no longer Tsarist, but Bolshevik. As early as November 1918, the Council of People’s Commissars (the Bolshevik government) made the decision to form, within the Red Army, the so-called Western Army, which was meant to serve the realization of the Soviet communists’ grand project: the world communist revolution. On March 10, 1920, a meeting of the leaders of the Red Army and communist commissars, including Stalin, took place in Smolensk, where the decisions were made to attack Poland and Europe. In the summer of 1920, the Red Army was advancing ominously toward the Vistula River, right to the gates of Warsaw.

In this dramatic situation, the Polish bishops, in order to awaken the consciences of all, sent letters: to the nation, to the Episcopates of the entire world, and to the Pope, asking Benedict XV for prayers and blessings for Poland threatened by the Bolsheviks. The bishops’ letter is of great importance and remains relevant today because it analyzes the communist ideology that the Bolsheviks wanted to impose on Europe and the world by force of arms. The bishops clarify that:

The bishops then wanted to make everyone aware that in this situation:

The concerns of the Polish bishops were well-founded because the Bolshevik leaders in Moscow were increasingly convinced of the possibility of conquering Europe. Lenin, during the 2nd Congress of the Comintern (the Communist International, the international organization of communist parties) in early August 1920, stated decisively: “Yes, Soviet troops are in Warsaw. Soon we will have Germany as well. We will reconquer Hungary, and the Balkans will rise against capitalism. Italy will tremble. Bourgeois Europe is cracking everywhere amidst this storm.” The military officers also flaunted confidence: Marshal Mikhail Tukhachevsky told the leaders of the Cossack cavalry brigades: “Before the end of the summer, the hooves of your horses will be heard on the streets of Paris.”

Unfortunately, despite the alarms raised by Poland, the world remained deaf to the Poles’ pleas for help. It seemed that everyone, including Western chancelleries, was resigned to a communist victory and, paralyzed, did nothing. In contrast, prayers for Poland began in various Churches, urged by the Pontiff himself.

(Marshal Pilsudski, architect of the victory at the Battle of Warsaw, with the Polish general staff).

The massive prayer campaign across the entire Church was mocked by socialist and communist circles in the West. The socialist newspaper Avanti! ridiculed the Pontiff’s initiative as follows: “The Pope is relying on the intercession of Our Lady. (…) The Roman Pontiff is sorely mistaken if he believes in the efficacy of the Virgin! Three million soldiers wear the Russian uniform. (…) These soldiers and their cannons will be worth far more than all the Rosaries in the world. In a few days, we will have the proof.” But reality was to disprove the contemptuous words of the Italian revolutionaries.

In those terrible months, with the Bolsheviks just a few kilometers from Warsaw, an extremely important role was played by Msgr. Achille Ratti, the first apostolic nuncio to reborn Poland. The Vatican Nuncio was the only diplomat, along with the Turkish ambassador, who did not leave the capital in August 1920 while the entire diplomatic corps fled in fear. Msgr. Ratti participated in the prayers organized during the Battle of the Vistula. He also made a very courageous and symbolic gesture that raised the morale of the fighters: he went to Radzymin on the frontline during the battle itself to make his presence felt among the soldiers. The future Pope Pius XI knew well what was truly at stake in the war, saying that “an angel of darkness was leading a gigantic battle with the angel of light”: for Pope Ratti, Poland would always remain the “bulwark (antemurale) of Europe and Christianity.”

Naturally, a paramount role was played by the Church in Poland itself, which mobilized the population to defend the Fatherland. Thanks to these appeals, people enlisted in the army en masse. Those who could not fight and stayed at home prayed, as the fear of Bolshevik occupation was immense—a fear fueled by reports of atrocities committed in already occupied areas. Priests also stood alongside Polish soldiers. One of them, in particular, entered history: Father Ignacy Skorupka, chaplain of the 236th Infantry Regiment composed of volunteers. Fr. Skorupka participated in the Battle of Warsaw always wearing his cassock. His regiment was fighting near the town of Wołomin and suffered heavy losses. At a certain moment, the chaplain realized he was the only surviving officer and had to take responsibility for 250 soldiers on his own shoulders: with a cross in hand as his only weapon, he led the young volunteers in a counterattack on enemy lines and died.

One cannot speak of the Battle of Warsaw without mentioning the heroic Polish fighters and the primary architect of the victory, Marshal Józef Piłsudski. This great Polish statesman realized the mortal danger that communism posed to Europe. But on the other hand, he was aware that Europe would not move to defend itself against this danger or grant aid to Poland. Thus, by defending his Fatherland, he was defending European civilization, which faced a grave risk because the young Polish army found itself in a dire situation: the Polish army was retreating along a 500-kilometer front before the advancing Russians. His advisors suggested organizing a defensive line along the Vistula around Warsaw to hold the capital at all costs. However, the Marshal realized that stopping nearly two million Bolshevik soldiers would require a vast number of troops that he did not have. On the night between August 5 and 6, he devised another plan, as risky as it was brilliant because it was entirely unexpected by the Russian commanders: from the remnants of the army, he formed 6 divisions that attacked the exposed flank of the Bolshevik Army south of Warsaw. To execute this maneuver, he had to strip the capital of its defense, but the maneuver succeeded completely: the Russian soldiers, entirely surprised by this daring attack, began to lose ground and were defeated before they could reorganize.

(Msgr. Achille Ratti [future Pope Pius XI], Nuncio to Poland, stayed in Warsaw during the battle).

When Achille Ratti became Pope, he wanted to build a new private chapel in the Apostolic Palace of Castel Gandolfo and had two paintings placed there, beside the portrait of Our Lady of Częstochowa, by the Polish painter Jan Henryk Rosen of Lviv depicting two events from Polish history: on one side, the defense of the Jasna Góra monastery in Częstochowa in 1655 against the Swedes, and on the other, the Battle of Warsaw—“The Miracle on the Vistula” itself—with the brave Fr. Skorupka leading the soldiers to attack with a cross in hand. This tribute by Pope Ratti to the defenders of Warsaw reminds us that we are all in their debt and that we must not forget it.

During the general audience on August 12, while greeting the Poles, Leo XIV spoke of the Battle of Warsaw: