Following the public calamities that struck the diocese of Vienne in the Dauphiné in the 5th century, Sr. Mamert established a solemn procession of penance on the three days before the feast of the Ascension. By a prescription of the Council of Orleans of 511, this custom spread to the rest of France.
In 816, Leo III adopted it for Rome and it was soon extended to the whole Church. The litanies of the Saints, the psalms and prayers sung in them, are prayers of supplication; hence their name Rogations. Without ceasing to implore God's blessings for the whole life of the Church, the Rogations became primarily, at this time of the year, a prayer for the abundance of the fruits of the earth. As a sign of penance, the colour purple is used and the paschal candle is not lit.
The chanting of the litanies gave its name to these three days of public prayer; but since Rome already had a similar procession on April 25, the Rogations took the name of Minor Litanies.
The Litanies of the Saints are an admirable type of prayer; they are very short conversational prayers. In the school of the Church, let us learn how to pray.
The whole Mass shows the effectiveness of the prayer of the just when it is humble, trusting and persevering. Elijah by his prayer closed and opened the heavens (Eph.) and Our Lord shows us by two parables that God gives his Holy Spirit to whoever asks him, because he is good (Ev., All.). In our afflictions let us put our trust in God and He will answer us as He answered Our Lord and exalted Him (Intr., Off.).