The confraternity formed to promote the crucifix, says Albinsky, soon became one of Rome's "most elite and influential".
It based its uniform—black habits with an image of the crucifix on the left shoulder—on the dress of many who originally marched.
By the middle of the 16th century, its membership had increased exponentially, and Albinsky estimates that 4% of the city's population were members.
The crucifix itself was protected, venerated and its stories promulgated by its sodality, which also limited physical access to it in order to heighten the mysticism surrounding it.
The confraternity's standing orders stated that:
So that more honoured, and with more devotion and greatness to His holy name, it be desired to see it, we order and decree that the most holy image of the most holy crucifix be kept closed with its keys and not opened but for four times a year.
Good Friday, the Feast of the Cross in May, the day of the procession of Corpus Christi, and the Feast of the Cross in September.

The crucifix was also led in procession to celebrate the return of England to the Catholic church under Queen Mary I in 1554.
The crucifix has since been carried in processions during the Jubilees, and the names of the popes who called each Jubilee were written on the back of it.

Contemporary Frescos on the oratory walls commemorating the founding of the confraternity—the Miraculous Survival of the Crucifix from the Fire in San Marcello and Procession of the Crucifix Against the Plague in 1522—reside in the church's oratory.
Every Easter since 1650 the crucifix has been carried from the church to St Peter's on the Thursday of Holy Week.
It has also been brought out on occasions of political and social emergency.
The confraternity formed to promote the crucifix, says Albinsky, soon became one of Rome's "most elite and influential". It based its uniform—black habits with an image of the crucifix on the left shoulder—on the dress of many who originally marched. By the middle of the 16th century, its membership had increased exponentially, and Albinsky estimates that 4% of the city's population were members. The crucifix itself was protected, venerated and its stories promulgated by its sodality, which also limited physical access to it in order to heighten the mysticism surrounding it. The confraternity's standing orders stated that:
So that more honoured, and with more devotion and greatness to His holy name, it be desired to see it, we order and decree that the most holy image of the most holy crucifix be kept closed with its keys and not opened but for four times a year. Good Friday, the Feast of the Cross in May, the day of the procession of Corpus Christi, and the Feast of the Cross in September.
The crucifix was also led in procession to celebrate the return of England to the Catholic church under Queen Mary I in 1554. The crucifix has since been carried in processions during the Jubilees, and the names of the popes who called each Jubilee were written on the back of it.
Contemporary Frescos on the oratory walls commemorating the founding of the confraternity—the Miraculous Survival of the Crucifix from the Fire in San Marcello and Procession of the Crucifix Against the Plague in 1522—reside in the church's oratory. Every Easter since 1650 the crucifix has been carried from the church to St Peter's on the Thursday of Holy Week. It has also been brought out on occasions of political and social emergency.
Crucifix of San Marcello