In the spring of 1916, three children - Lúcia dos Santos, Francisco and Jacinta Marto - had reported three apparitions from an Angel in the countryside of Valinhos. Following that, from May 1917, six apparitions of the Virgin Mary were reported in the area of Cova da Iria. The children described the Lady as "a Lady more brilliant than the Sun". A prophecy that prayer would lead to the end of WW1 was reported, and that on 13 October that year, the Lady would reveal her identity and perform a miracle so all will believe. Newspapers started reporting this and many pilgrims flocked to the site. The children's accounts drew intense criticism from both secular and religious authorities. An administrator brought them into custody as he believed the prophecies were politically motivated against the secular 'First Portuguese Republic' started in 1910. 

On 13 May 1917, the children reported a woman, "brighter than the sun, shedding rays of light clearer and stronger than a crystal goblet filled with the most sparkling water and pierced by the burning rays of the sun". She asked them to be devoted to the Trinity and to pray the Rosary every day, "to bring peace to the world and an end to the war". The children never told anyone about seeing this angel, but Jacinta told her family about it. Lúcia had said before to keep this experience private. Jacinta's mother told neighbours about the story as a joke, and the whole village quickly knew about the vision.

The children said that the woman told them to return to the Cova da Iria on 13 June 1917. Lúcia's mother asked for help from the parish priest (Father Manuel Ferreira), who suggested she allows them to go. He then asked to be able to question Lúcia after this. This second apparition happened on 13th of June, St Anthony's feast day, patron of the local parish. Lúcia later reported that the Lady revealed that Francisco and Jacinta would be taken to heaven soon, however Lúcia lives longer to spread the message and devotion to the Immaculate Heart of Mary. 

During the June Apparition, the children reported that the lady said to say the Rosary each day in honour of Our Lady of the Rosary to bring peace and the end to the Great War. The lady also revealed hell to the children, entrusting a secret to them, "good for some and bad for others". Fr Ferreira stated that Lúcia recalled the lady telling her, " I want you to come back on the 13th, and to learn to read in order to understand what I want of you.. I don't want more."

In the following months, thousands came to Fátima, and on 13 August 1917, the administrator intervened. Taking them into custody, he jailed them before they could reach the Cova da Iria as he believed the events were politically disruptive (as explained above). He interrogated and threatened the children to divulge the secrets. Lúcia's mother hoped the administrator could get the children to end the kerfuffle and admit they lied. Lúcia told him everything except for the secrets, and offered to ask the lady for permission to tell the secrets. 

That month, the usual apparition on 13 August, happened instead on 19 August in Valinhos. Again, she asked them to pray the rosary daily, spoke of the miracle coming in October, and asked them to pray for the sinners and sacrifice lots.