In times of calamity litanies were held, in which the people walked in robes of penitence, fasting, barefooted, and, in later times, frequently dressed in black ("litaniae nigrae"). The cross was carried at the head of the procession and often the gospel and the relics of the saint were carried. Gregory of Tours gives numerous instances of such litanies in time of calamity; thus he describes a procession of the clergy and people round the city, in which relics of St Remigius were carried and litanies chanted in order to avert the plague. So, too, Gregory the Great writes to the Sicilian bishops to hold processions to prevent a threatened invasion of Sicily. A famous instance of these penitential litanies is the "litania septiformis" ordered by Gregory the Great in the year 590, when Rome had been inundated and pestilence had followed. In this litany seven processions, of clergy, laymen, monks, nuns, matrons, the poor, and children respectively, starting from seven different churches, proceeded to hear mass at St. Maria Maggiore. This litany has often been confused with the "litania major", introduced at Rome in 598 (vide supra), but is quite distinct from it.