It was instituted by Pope Urban IV in 1264 after the famous Miracle of Bolsena.
In papal Rome every year on Corpus Domini day a solemn procession was led by the pope from the Sistine chapel along the Borgo neighborhood. The pope holding the sacrament was carried on his chair and followed by cortege of about 3.000 people among cardinals, prelates, clergy, Swiss guards and noblemen.
It was also an occasion of party and noise for the people that took advantage of every occasion to party.
Every roman citizen was required to addend the procession except the prostitutes and the ladies.
It was one of the rare occasions when all social classes were together side by side. The itinerary of the parade was entirely decorated with flowers and the houses were decorated with colored carpets and religious images. The parade was suspended in 1870 but it has been restored in 1979 by John Paul II.
Since then, every Thursday after the Holy Trinity day the procession takes place from San Giovanni in Laterano cathedral to Santa Maria Maggiore basilica along the Merulana road.
Corpus Domini Celebration, Painting by unknown artist – 1650 Museo di Roma