Monti is the name of one of the twelve “rioni”(sub-district) of Rome, namely rione I. The name literally means “mountains” in Italian, and it comes from the fact that the Esquiline and the Viminal Hills, and parts of the Quirinal and the Caelian Hills, belong to this rione. On its cote of arms there are three green mountains with three peaks on a silver background. Nowadays the districts Esquilino, Castro Pretorio and Celio do not belong to Monti anymore, but the rione has retained its former name. In ancient times the district was densely populated, as it contained the Forum Romanum and the so-called Suburra(“suburbs” in Latin). The latter was the place where poor people lived, full of disreputable locals and brothels.

In the Middle Ages the situation changed completely: the Roman aqueducts were damaged, and it was very difficult to bring water to Monti, since it was on a hill. That is why lots of inhabitants moved to Campus Martius, a lower part, where they used to drink water from the river Tiber. From the Middle Ages to the beginning of the 1800s, the rione remained an area full of vineyards and gardens. Monti was not very populated because of the lack of water and because it was quite distant from the Vatican, the centre of Christian culture. The area was however never abandoned thanks to the church of San Giovanni in Laterano and the huge number of pilgrims continuously visiting it. Since the Middle Ages the inhabitants of Monti, called “monticiani“, developed a strong sense of identity: their Roman dialect was different from that spoken in other rioni. Their main enemies were the people from the other rione with a strong identity, “Trastevere” (Trastevere = Trans Tevere, the other side of the river Tevere), and they often used to fight against one another. The increased urbanization of late nineteenth century, when Rome became the capital of a unified Italy, and the great changes brought about by the Fascist period, modified completely the appearance of the rione. Between 1924 and 1936 a big part of the rione, made of small streets and popular houses, was destroyed to built via dei Fori Imperiali (the street artificially dividing the Roman Forum and most of the Imperial Fora), and the archaeological buildings of the forum Romanum were dug out from under the ground.

from  www.wikipedia.org