On this day, Portugal celebrates the Day of Our Lady of Fatima.
Many years ago, on May 13, 1917, after Sunday mass, three little shepherds Jacinta, Francisco and Lucia from Cova da Iria, near the small Portuguese town of Fatima, were pasturing their sheep not far from home. Suddenly lightning flashed, and they decided that a thunderstorm was beginning. She needed somewhere to hide the sheep.
At that moment, an image of the Most Holy Theotokos appeared to them, which, according to them, sparkled brighter than the sun. When the children told the adults about it, no one believed them, but the miracle was repeated on the 13th of every next month until October.