Following the expulsion of the last Tarquin king in 509 B.C., the Romans inaugurated the larges Tuscan temple ever made, dedicated to Jupiter, Juno, and Minerva on the southern summit of the Capitoline Hill. The architecture employed was still that of the Etruscan world. Rome, however was destined to affirm its presence and language over the entire Mediterranean region, with a history that began with the destruction of Veii itself in 396 B.C. Over the span of two centuries, Roman architecture succeeded in drawing ideas from the Greek and Magna Graecia world to express an autonomous identity that reflected Latin society and its cults. From temples to basilicas, and from imperial residences to bathing complexes, theatres and amphitheatres, every structure spoke a “Roman” language. Great structures that revolutionized the very concept of architectural space throughout the ancient world. Its lexicon was soon adopted by all the cities of the empire.


Just as in Greece, the oldest monumental structures in the Italic world were massive walls built in defence of cities. These structures were made without the use of lime mortar, and the large blocks of stone, which in the earliest periods were given only the most rudimentary shaping, were set directly or top of each other.

The most commonly employed construction technique using large blocks was opus quadratum . This method appeared in Rome as early as the sixth century B. C. (the Temple dedicated to Jupiter on the Capitoline hill). This method was adopted for the construction of numerous buildings, as in the Forum of Caesar built in the first century B.C or the Forum of Augustus, finished in the year 2 B.C, as well as the outer walls at the nearby Forum of Nerva.


The Greek building tradition included the custom of making walls composed of two facing walls filled by a core of argillaceous soil and stones. The Romans soon intuited that by replacing the argillaceous soil of the core with a good quality lime mortar, they could build a wall of greater strength. Thus they developed opus caementicium, to which Vitruvius refers: “the work  is to be filled in with concrete of stone, lime and sand” .The aggregates (Lat.caementa) were of diverse kinds, from pebbles to irregular bits of stone, from brick fragments to other terracotta goods such as broken pieces of amphorae. These materials were far more economical than squared stone and provided walls with significant static capacities.

The technique of opus caementicium began spreading from Latium and Campania around the end of the third century B.C. A long process of experimentation was necessary to perfect the execution of this technique. Vitruvius wrote that the walls should “be built with very minute stones; so that the walls, thoroughly saturated with mortar of lime and sand, may hold longer together For since the stones are of a soft and open nature, they dry up the moisture by sucking up out of the mortar. But when the supply of lime and sand is abundant, the wall having more moisture will not quickly become perishable, but holds together.” (2.8.2-3)