The original icon from Church Maria Maggiore in Rome. The icon is also known as: Virgin Salus Populi Romani (the virgin that saved the population of Rome).
There are numerous copies of this icon. Here is an example of a Russian one:
Here follows a lexical description of the icon in Church Maggiore
Salus Populi Romani, meaning Protectress (literally "Health") of the Roman People is the title given in the 19th century to the icon of the Madonna and Child, reputed to date to Early Christian times, in the Santa Maria Maggiore Basilica in Rome. It is historically the most important Marian icon in Rome, although devotion to it has declined somewhat relative to other images over the last two centuries. The phrase Salus Populi Romani (as 'Health or well-being of the Roman people') goes back to the legal system and pagan rituals of the ancient Roman Republic, where Livy tells us that the augur would ask the gods for permission for the praetors to pray for it.
For centuries it was placed above the door to the basilica's baptistery, and in 1240 it was called Regina Caeli ("Queen of Heaven") in a document. Later it was moved to the nave, and from the 13th c. it was preserved in a marble tabernacle. Since 1613. it has been located in the altar tabernacle of the Cappella Paolina (built specifically for it), known to English-speaking pilgrims as the Lady Chapel. The church, Saint Maria Maggiore, is considered the third of the Roman patriarchal basilicas. The church and its Marian shrine are under the special patronage of the popes.
From at least the 15th century, it was honored as a miraculous image, and it was later used by the Jesuits in particular to foster devotion to the Mother of God through the Sodality of Our Lady movement.
The Roman Breviary states, "After the Council of Ephesus (431) in which the Mother of Jesus was acclaimed as Mother of God, Pope Sixtus III erected at Rome on the Esquiline Hill, a basilica dedicated to the honor of the Holy Mother of God. It was afterward called Saint Mary Major and it is the oldest church in the West dedicated to the honor of the Blessed Virgin Mary." The Roman Pontifical gives an additional account, "The Liberian basilica, today called Saint Mary Major, was founded by Pope Liberius (352-366) and was restored and enlarged by Sixtus III. ... Pope Liberius selected a venerated picture that hung in the pontifical oratory. It had allegedly been brought to Rome by St. Helena."
Among many evidences of papal devotion, the current Pope Benedict XVI twice referred to Mary as the "Salus Populi Romani" during the funeral prayers for his predecessor John Paul II 
Legend of Saint Luke
Salus Populi Romani is one of the so-called "Luke images" of which there are many throughout the world. These were believed to have been painted from the life by Saint Luke himself. According to the legend: "after the Crucifixion, when Our Lady moved to the home of St. John, she took with her a few personal belongings--among which was a table built by the Redeemer in the workshop of St. Joseph. When pious virgins of Jerusalem prevailed upon St. Luke to paint a portrait of the Mother of God, it was the top of this table that was used to memorialize her image. While applying his brush and paints, St. Luke listened carefully as the Mother of Jesus spoke of the life of her son, facts which the Evangelist later recorded in his Gospel. Legend also tells us that the painting remained in and around Jerusalem until it was discovered by St. Helena in the fourth century. Together with other sacred relics, the painting was transported to Constantinople where her son, Emperor Constantine the Great, erected a church for its enthronement." 
The image is five feet high by three and a quarter feet wide (117 x 79 cm) - very large for an icon, especially one with an early date. It is painted on a thick cedar panel. Mary wears a gold-trimmed dark blue mantle over a purple/red tunic. The letters in Greek at the top identify Mary as "Mother of God", as is usual in Byzantine art (Christ may originally have had an inscription under later re-painting). Christ is holding a book in his left hand, presumably a Gospel Book. His right hand is raised in a blessing gesture, and it is Mary not he who looks directly out at the viewer.
The folded together position of Mary's hands distinguishes this image as a version of the earlier type from before the development of the iconography of the Hodegetria image in the 10th century, where she points to Christ with her right hand. "Rather than offering the Child, she keeps his body closer to hers and seeks physical and tactile contact with him" However the few other examples of this type do not have the Virgin's hands folded together - the right hand holds Christ's knee.
Although neither wear crowns, the holding by Mary in her right hand of a mappa (or mappula, a sort of embroidered ceremonial handkerchief), originally a consular symbol, later an imperial one, means this image is probably one of the type showing Mary as Regina coeli or "Queen of Heaven".
Dating by art historians
The image "has been confidently dated to almost every possible period between the fifth century and the thirteenth". The recent full-length study by M. Wolf (see further reading) "says, cautiously, that it is probably Late Antique" in its original form.
The icon in its current state seems to be a work of the thirteenth century (as witnessed by the features of the faces), but other layers visible under the top one suggest it is a repainting of a much earlier piece; especially revealing is the modeling of Child's right hand in the first layer, which can be compared to other early Christian icons that display 'Pompeian' illusionistic qualities  The areas of linear stylization, such as Christ's garment which is rendered in golden hatching producing a flat effect, seem to go back to the 8th century, and can be compared with a very early icon of Elijah from Sinai. A second restoration process started around 1100 and came to an end in the 13th c. Virgin's blue mantle which is wrapped over her purple dress was severely altered in the outline; the red halos are also not part of the original image.
The image type itself suggests it is not a medieval invention, but rather an Early Christian concept dating from antiquity: a majestic, half-length portrait showing a frank outward gaze of the rulerlike Virgin, with her upright, stately pose, and folded hands gently clasping the Child, unique among all icons. Lively turning of the maturely developed and attired Child also attests to the painting's antiquity. The vivid contrapposto of the two bodies, which suggests direct observation, can be compared with 5th c. Mount Sinai icon of the Virgin and Child in Kiev, and contrasted with Pantheon Marian icon from 609. which already shows Mother slightly subordinated to the Child by the imploring gesture and the turn of the head, and where the interaction of the bodies exists only in a flat plane. These comparisons suggest a date of 7th c. for the icon.
The early fame of the icon can be gauged from the production of replicas (a fresco in Santa Maria Antiqua seems to have reproduced it already in the 8th c.), and the role it played in the ritual on the feast of the Virgin's Assumption, where the achiropiite (the panel painting of Christ from the Lateran Basilica) was moved in a procession to Santa Maria Maggiore to 'meet' with it. More far flung apparent copies include a Moghul miniature, presumably based on a copy given to Akbar by the Jesuits, and copies in China, of which a 16th century example is in the Field Museum in Chicago.