A defined pattern can be observed in the curious votive niches: the most of them are placed at a certain height from the ground, probably to avoid damages from people and carriages. The height looks consistent with the position of sacred icons in churches and chapels, but it must be noted that, in case of alleys and other tiny roads, they are located at around 1 meter of height from the ground, so to allow common gestures of devotion.
Even if the structure of a Madonnella is considered quite simple (baldaquin, image and light) it must be noted that many differents tecniques and materials are used for their creation.
The majority of them are paintings on canvas or wood, but some of them are frescoes, mosaics, relieves or statues.
Among the most used materials figure stucco (expecially used for the decorations framing the icons) and terracotta. Very little Madonnelle were realized in marble or ceramics. This last material was usually "suggested" by glazing the terracotta bas-relieves.
The Madonelle were in fact the results of private committences, but they were usually supported by noble families, churches or friar orders. An obvious example of this tendency can be witnessed by the Madonnelle decorating the walls of private buildings. These Madonnelle were not just placed on corners or crossroads, but directly on the facade or walls of the palace, preferably in between windows, so to allow their maintenance.
Despite the more or less powerful committence, the Madonnelle were indeed the source of a blatant and extreme popular devotion, as many of them are still considered miraculous images because of their portents.
There are many stories and legends about miracles that have the Madonnelle as protagonists: some of them cried blood before invasions, flowings or pestilences, others bleeded when offended, another let the flowers placed in front of it to not wither for several months.
But the most curious and disturbing miracle involved a good number of Madonnelle from the 9 July of 1796 and continuing for 20 days: an impressive number of Madonnelle in Rome, in fact, was witnessed while moving their eyes alarmingly and cry, as to alert the population of a close threat.
The event was so blatant and widespread that the Roman Inquisition investigated. Among the many Madonelle just five (that were already quite popular, some of them venerated by Popes themselves) were recognized as miraculous... Plaques and tags around them still remind the distracted walker of their portent.
They are called "Madonnelle" because the most of them portray the Virgin Mary, a favourite among Catholics as she's the "sample" of a mere human being elevated to Sanctity due to the intercession of Jesus her son, but the sacred images of Rome don't involve the Virgin Mary alone. Following are a few examples featuring the Sacred Family, Saints and Jesus.
Popular, aristocratic or "fake", they are indeed an interesting contribution to the understanding of Rome and its way to live religion, inbetween fervent devotion, naive superstition and popular gratitude.
If you wish to know more about the Madonnelle, I suggest you to take a peek to this extraordinary website, and for a complete list with addresses and details, you can check this page out!