Fatima is today one of the most important pilgrimage sites in the Christian world: every year millions of faithful reach this small town in central Portugal, about 125 kilometres north of Lisbon. At the centre of everything are the events that took place between 13 May and 13 October 1917, when — according to the accounts of the seers — the Virgin Mary appeared to three young shepherd children, in a Portugal marked by the recent anticlerical Republic and the suffering of the First World War. The apparitions, culminating in the famous "Miracle of the Sun" on 13 October before tens of thousands of people, transformed a poor farming village into a global spiritual landmark. From here emerged a message of conversion, prayer and peace that has accompanied the religious history of the 20th century, spanning two world wars, the Cold War and the fall of totalitarian regimes.