Pope Leo marks All Souls' Day in a Roman cemetery
Pope Leo XIV celebrated Mass for All Souls' Day on Monday at Rome's Campo Verano cemetery, praying for the dead and especially for those who have lost loved ones to war. "May the tears of so many mothers, so many children, and so many elderly people touch the consciences of those who have the power to silence the weapons," he said, according to Vatican News. He leaves for South America later this week. Read at Vatican News →
Abbot Odilo of Cluny creates All Souls' Day
What happened then
During his long rule as abbot of Cluny (994–1049), Odilo ordered that every monastery in Cluny's network keep an annual day of prayer for all the faithful departed, on November 2, the day after All Saints. Sources differ on the exact year, placing it in the late 10th or early 11th century.
What caused it
Christians had prayed for their dead since the earliest centuries, writing their names on lists read at the liturgy. But local customs varied widely: Benedictine monks remembered their dead around Pentecost, Spain had its own day in the time of Isidore of Seville, and parts of Germany prayed for the dead on October 1. Cluny, then the most important monastery in Western Europe, had the reach to set one common date.
How it was resolved
The practice spread quickly beyond Cluny's houses to other Benedictines and to the Carthusians. The diocese of Liège was the first to adopt it, under Bishop Notger, who died in 1008, and other dioceses followed, until it was kept across the Western Church.
How it turned out
All Souls' Day is still observed on November 2 throughout the Catholic world and in parts of the Lutheran and Anglican traditions, with Masses for the dead and family visits to decorate graves. Eastern Orthodox churches kept their own separate days for remembering the departed.
Sources: Catholic Encyclopedia (1907): All Souls' Day (New Advent) · Wikipedia: Odilo of Cluny · Wikipedia: All Souls' Day
Further reading: Hamlet in Purgatory by Stephen Greenblatt