The procession from San Luca until the city centre of Bologna is a centuries-old tradition which takes place since XV century, when, in a period of natural calamities, the citizens entrusted themselves to the Madonna's effigy to tone down the catastrophe. Ever since, the Saturday before the fifth Sunday after Easter (since 1977, however, on that very Sunday), the effigy comes down sorrounded and escorted by the believers from the sanctuary, staying in the city for a few days.