More than 250,000 Roman Catholic pilgrims are expected to converge on the shrine of Fatima in Portugal over the next three days for the opening of one of the world's largest churches.
The Vatican's secretary of state, Cardinal Tarcisio Bertone, Friday presided over the ceremonies dedicating the new Church of the Holy Trinity at the shrine. Officials say Pope Benedict will deliver a live televised message Sunday to the pilgrims in Fatima.
The ceremonies focus on Saturday's 90th anniversary of the last time many Catholics believe the Virgin Mary appeared before three Portuguese shepherd children.
The three children said Mary, the mother of Jesus, delivered to them in 1917 a series of apocalyptic visions of the future.
Church officials say at least five million people travel to the site of the apparitions each year.
Officials say the new church can accommodate nearly nine thousand worshippers.
Sister Lucia, the last of the three children, died in 2005.
She and her two cousins, Jacinta and Francisco, said the Virgin Mary appeared to them several times. The children said she predicted such events as World War Two, the communist takeover in Russia and the later re-emergence of Christianity in that country. The two cousins died within several years of the apparitions.