In the spring and summer of 1916, nine-year-old Lúcia Santos and her cousins Jacinta and Francisco Marto were herding sheep at the Cova da Iria near their home village of Fátima, Portugal. They claimed to have experienced the visitation of an angel on three separate occasions. The angel taught them prayers to pray, to make sacrifices, and to spend time in adoration of the Lord. On May 13, 1917, Lúcia described seeing a lady "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". While they had never spoken to anyone about the angel, Jacinta divulged her sightings to her family despite Lucia's admonition to keep this experience private. Her disbelieving mother told neighbors as a joke, and within a day the whole village knew. Further appearances were reported on June 13 and July 13. In these, the lady asked the children to do penance and Acts of Reparation and make personal sacrifices to save sinners. According to Lúcia's account, the lady also confided to the children three secrets, now known as the Three Secrets of Fátima.
The children subsequently wore tight cords around their waists, performed self-flagellation using stinging nettles, abstained from drinking water on hot days, and performed other works of penance. Thousands of people flocked to Fátima and Aljustrel in the following months, drawn by reports of visions and miracles. On August 13, 1917, the provincial administrator Artur Santos (no relation to Lúcia Santos), believing that the events were politically disruptive, intercepted and jailed the children before they could reach the Cova da Iria. The administrator interrogated and threatened the children to get them to divulge the contents of the secrets. Lúcia told him everything short of the secrets, and offered to ask the Lady for permission to tell the Administrator the secrets. Prisoners held with them in the provincial jail later testified that the children led them in praying the rosary. That month, instead of the usual apparition in the Cova da Iria on the 13th, the children reported that they saw the Virgin Mary on 15 August, the Feast of the Assumption, at nearby Valinhos.