Mary Help of Christians

Mary Help of Christians (Latin: Sancta Maria Auxilium Christianorum), is a Roman Catholic Marian devotion with a feast day celebrated on May 24. John Chrysostom was the first person to use this title in 345 as a devotion to the Virgin Mary.
The devotion became popular in Europe during the pontificate of Pope Pius V and the fights against the Ottoman Empire. It was definitely established due to the great appreciation of Don Bosco for this Marian title and the development of the Salesian works in several countries since the second half of the 19th century. Although it is commonly associated with the Roman Catholic Church, the Orthodox Church has also known the devotion since 1030 in Ukraine, when the country was defended from a barbarian invasion.
The title of Mary Help of Christians is associated with the defense of Christian Europe (Latin and Greek), the north of Africa and the Middle East from non-Christian peoples during the Middle Age. In 1572, the Islamic Ottoman Empire intended to invade Christian Europe. Pope Pius V called Christian armies from all over Europe to defend the continent and asked the believers to pray to Mary in order to help the Christians. The defeat of the Muslim Turks was attributed to the intercession of Mary under this title.
Around 1576, Bernardino Cirillo, archpriest of Loreto, published at Macerata two litanies of the Blessed Virgin, which, he contended, were used at Loreto. One is in a form which is entirely different from our present text. Another form ("Aliae litaniae B.M.V.") is identical to the litany of Loreto approved by Pope Clement VIII in 1601 and now used throughout the entire Church. This second form contains the invocation Auxilium Christianorum. Possibly the warriors, who returning from the Battle of Lepanto (October 7, 1571) visited the sanctuary of Loreto, saluted the Holy Virgin there for the first time with this new title. It is more probable, however, that it is only a variation of the older invocation Advocata Christianorum, found in a litany of 1524.
Torsellini (1597) and the Roman Breviary (May 24, Appendix) say that Pope Pius V inserted the invocation in the litany of Loreto after the battle of Lepanto. But the form of the litany in which it is first found was unknown at Rome at the time of Pius V.
The feast of Our Lady, Help of Christians, was instituted by Pope Pius VII. By order of Napoleon I of France, Pius VII was arrested on June 5, 1808, and detained a prisoner for three years at Savona, and then at Fontainebleau. In January 1814, after the battle of Leipzig, he was brought back to Savona and set free on March 17, on the eve of the feast of Our Lady of Mercy, the Patroness of Savona. The journey to Rome was a veritable triumphal march. The pontiff, attributing the victory of the Church after so much agony and distress to the Blessed Virgin, visited many of her sanctuaries on the way and crowned her images (e.g., the "Madonna del Monte" at Cesena, "della Misericordia" at Treja, "della Colonne" and "della Tempestà" at Tolentino). The people crowded the streets to catch a glimpse of the venerable pontiff who had so bravely withstood the threats of Napoleon. He entered Rome on May 24, 1814, and was enthusiastically welcomed.
After the Congress of Vienna and the battle of Waterloo, the Pope returned to Rome on July 7, 1815. To gave thanks to God and Our Lady, on 15 September 1815 he declared 24 May, the anniversary of his first return, to be henceforth the feast of Our Lady, Help of Christians; the 1913 Catholic Encyclopaedia article commented that it has spread nearly over the entire Latin Church, but is not contained in the universal calendar.