Litaniae Sanctorum: Litany of the Saints

The Litany of the Saints is prescribed by the Roman Ritual at the laying of the corner-stone of a new church, at the blessing or reconciliation of the same or of a cemetery, in the rite of blessing the people and fields in virtue of a special papal indult, for the major and minor Rogation Days, in the procession and prayers to obtain rain or fine weather, to avert storms and tempests, in time of famine or war, to escape mortality or in time of pestilence, in any tribulation, during the translation of relics, in solemn exorcisms of the possessed, and at the Forty Hours' Devotion. The Roman Pontifical, besides the occasions given in the Ritual, orders its recitation in the conferring of major orders, in the consecration of a bishop, benediction of an abbot or abbess, consecration of virgins, coronation of a king or queen, consecration of a church, expulsion and readmission of public penitents on Maundy Thursday, and in the "Ordo ad Synodum". - From the Catholic Encyclopedia