The Main Apparitions of Our Lady

Apparitions of Rue du Bac, Paris
The apparitions of Our Lady at Bayside, New York, continue in the long tradition of modern Marian apparitions that started with the Apparitions of the Virgin Mary at Rue Du Bac in Paris to Catherine Labouré in 1830. In this apparition, the Blessed Virgin initiates Her End Days battle with the Devil, as symbolized in the “Miraculous Medal,” where Our Lady is pictured as standing on a globe of the world, with the Serpent crushed beneath Her feet. This alludes to the Woman in Genesis, while the twelve stars on the Medal allude to the Woman of the Apocalypse, whose head is surrounded by twelve stars, who now battles in the Devil, pictured as a huge Red Dragon.

The Virgin Mary at La Salette, France
In 1846, Our Lady gave apocalyptic Secrets to two children, Melanie Calvat, aged 14, and Maximin Giraud, aged 11, on a mountain in the French Alps. The Bessed Virgin gave them each an apocalyptic secret Message. Here is Maximin's Secret. You may read Melanie's secret at The Apparitions of Our Lady of La Salette in 1846, France.

The Appearance at Knock, Ireland
In 1879, Our Lady, St. Joseph and St. John the Evangelist appeared on the side of a church, in a blaze of light, with an altar

and a lamb and a cross. This seemed to indicate that the unfolding of the Apocalypse was about to begin. There was no Message given.

Apparitions of Our Lady at Fatima
In 1917, the Virgin Mary appeared to three shepherd children, where She gave them three secrets: 1) A vision of Hell 2) That World War I would soon end, but a worse war would break out under the Pontificate of Pius XI, if people didn't amend their lives. She also announced that She would come to ask for the Consecration of Russia to Her Immaculate Heart and the communion of reparation on the First Saturdays. If Her requests went unheeded, Russia would spread its errors throughout the world, promoting wars and persecution of the Church.
For the 3rd Secret, you can get some details at Fatima's Third Secret.

Apparitions at Heede, Germany
Our Lady appeared to four girls at Heede, a small village in northern Germany in 1937. However, Jesus Himself delivered an apocalyptic Message to one of the girls, Greta Gansforth: “Tremendous things are in preparation; it will be terrible as never before since the foundation of the world. All those who in these grave times have suffered so

  much are martyrs and form the seed for the new Church. They were privileged to participate in My captivity, in My scourging, in My crown of thorns and My way of the Cross!” You can read the complete Message at: Apparitions of Our Lady of Heede.

Apparitions at Marienfried, Germany
A series of apparitions of the Blessed Virgin to Barbara Reuss began on April 25, 1946, where She revealed Herself as the Mediatrix of All Graces. The following is an excerpt from Her Message: “In secret I shall work marvels in souls until the required number of victim souls will be filled. Upon you it depends to shorten the days of darkness. Your blood and your sacrifices shall destroy the image of the Beast. Then I can manifest myself to the world for the glory of the Almighty. Choose my Sign, so that the Triune God may soon be adored and honored.” You can read the rest at Our Lady of Marienfried.

The Virgin Mary appears to Veronica
Our Lady at Bayside, NY confirms the 3 great events at Garabandal, but adds that the Chastisement is in two parts: 1) World War 3; 2)The world will be comet-struck; and only one-quarter of mankind will survive. This will be followed by the period of Peace, as promised by Our Lady of Fatima.