Fátima has been Portugal’s leading Catholic site of pilgrimage for a century, since three child shepherds had a series of visions of the Virgin May there in 1917.

The international pilgrimage, which takes place over two days, also includes the National Pilgrimage of Migrants and Refugees, but most pilgrims are likely to be Portuguese emigrants who take advantage of the summer holidays to travel to Fátima.

Presiding over the event will be Marc Ouellet, former Archbishop of Quebec, who was once seen as a candidate to succeed Pope Benedict XVI. A member of the Society of the Priests of Saint-Sulpice, he has been a cardinal since 2003 and the prefect of the Congregation for Bishops and president of the Pontifical Commission for Latin America since 2010.

The pilgrimage is also to remember the Berlin Wall, which was built from 12 to 13 August 1961 and divided the city of Berlin in two for almost 30 years, the shrine notes. The traditional candle-light procession on Monday night is to make a stop next to the piece of the wall that stands in the shrine since it was donated by a Portuguese resident in Germany, with prayers to be said there.

The pilgrimage is formally to start at 6.30 p.m. in the Chapel of Apparitions. Later there is to be a recitation of the rosary, followed by the candle-light procession and Vigil Mass.

The international mass begins at 10 a.m. on Tuesday and includes "the traditional offering of wheat by pilgrims at the moment of the presentation of gifts", according to a statement from the shrine authorities.