The term Forty-Hours designates an urgent supplication from God through adoration of the Blessed Sacrament solemnly exposed for 40 hours.
This supplication takes place most often and by tradition during the hours preceding the opening of Lent, from Quinquagesima Sunday to the Tuesday before Ash Wednesday, but can be done at other times of the year.
The Forty Hours Devotion—as an exceptional supplication—first began in Milan in 1527, in the context of wars and calamity (the sack of Rome and the French invasion of Milan). They were instituted there by Jean-Antoine Bellotti at the beginning of each quarter, and kept up until 1529.
In 1537, the Milanese Capuchin Giuseppe da Ferno took them over and made them a chain of solemn prayers with a Eucharistic procession: when one parish ended its Forty Hours, another took over, so that the Blessed Sacrament was adored perpetually (this practice is the origin of perpetual adoration).
St. Antoine-Marie Zaccaria (1502 † 1539), founder, again in Milan, of the Clerics Regular of St. Paul (or the Barnabites) ardently propagated them.
In 1575, the Archbishop of Milan, St. Charles Borromeo, in a pastoral letter of admirable eloquence on the holiness of the time of Septuagesima, deplored the misfortune of free Christians who so badly used these precious days, during which they should be applying themselves especially to prayer and good works.
To this end, St. Charles set up the organization of the Forty Hours devotion in the largest diocese in Europe that he directed: the Blessed Sacrament would be exhibited on the three days preceding Lent in the cathedral of Milan and in thirty other city churches; in the morning and in the evening there would be a solemn procession, and the parish priests would distribute the hours of the day among their parishioners, so that there was always a fairly large number of worshipers before the Blessed Sacrament.
On November 25, 1592, Pope Clement VIII, by the Constitution Graves et diuturnæ, organized the Forty Hours Devotion in the City of Rome in the manner in which Giuseppe da Ferno had done previously: in a continuous flow, prayers would begin in a particular Roman church at the moment at which they ended in another.
By instituting them, the Pope asked that the Forty Hours Devotion then be performed for 3 intentions:
1.for the salvation of the kingdom of France, then torn apart by the succession of Henry III,
2.for the victory of Christendom against the Turks,
3. for the unity of the Church.
The Pope began this chain of prayers on November 30, 1592 at the Sistine Chapel.
Thereafter, the Church has asked Christians to offer Eucharistic adoration in reparation for public sins. Today, the loss of faith and the silent apostasy of entire sections of humanity, the civil laws contrary to the Decalogue, and the various forms of revolt against God and against His Christ must mobilize the prayer of supplication: it serves to implore the mercy of Jesus Christ on the Church, on society, and on the world.
The present times are not lacking in prayer intentions which should encourage everyone, as much as possible, to participate in this beautiful institution of the Forty Hours Devotion.