Roman architecture

The Romans adopted the external language of classical Greek architecture for their own purposes, which were so different from Greek buildings as to create a new architectural style. The two styles are often considered one body of classical architecture. Sometimes that approach is productive, and sometimes it hinders understanding by causing us to judge Roman buildings by Greek standards.

Roman architecture represents a fusion of traditional Greek and Etruscan elements, notably the trabeated orders, with new structural principles based on the development of the arch and of a new building material, concrete. The Romans achieved originality in building very late in their existence; for the whole of the republican period, Roman architecture was heavily influenced by Greece, aside from the Etruscan contribution of the arch, and its later three-dimensional counterpart, the dome. The only two developments of any significance were the Tuscan and Composite orders; the first being a shortened, simplified variant on the Doric order and the Composite being a tall order with the floral decoration of the Corinthian and the scrolls of the Ionic.

Like much of Roman art, there is an eclectic aspect to Roman architecture. Not only did building designers borrow from the Etruscans, but also from the Greeks. There are records in Rome indicating that many architects working in the city during the late Republic and early Empire were Greek or of Greek descent. Although the Romans used innovative materials like brick and concrete throughout the Empire, they almost always used Greek architectural orders to decorate the exteriors of their buildings. For example, the facade of the Colosseum — Rome's monumental amphitheater — is decorated with columns in the Doric, Ionic, and Corinthian orders. In the later periods of Roman dominance, a greater Eastern influence can be seen in the architecture of the time. From the second century CE on, materials like Proconnesian marble from modern-day Turkey and architectural details native to other eastern provinces become more prominent in buildings in Italy and the west. The Roman architects were not slavish imitators, however, and combined Greek, Etruscan, and provincial design elements in new and groundbreaking ways. The Temple of Portunus near the Tiber River in Rome demonstrates this concept well. The building is similar to an Etruscan temple with its high podium, columned porch, and focus on the front of the building. The use of freestanding columns on the front of the building and half-columns on the sides and back in the Corinthian order, however, is clear evidence of Greek influence. It is this careful selection and combination of different forms that makes this temple a distinctly Roman one.

Innovation started in the first century BCE, with the invention of concrete, a stronger and readily available substitute for stone. Tile-covered concrete quickly supplanted marble as the primary building material and more daring buildings soon followed, with great pillars supporting broad arches and domes rather than dense lines of columns suspending flat architraves. The freedom of concrete also inspired the colonnade screen, a row of purely decorative columns in front of a load-bearing wall. In smaller-scale architecture, concrete's strength freed the floor plan from rectangular cells to a more free-flowing environment.

Although concrete had been used on a minor scale in Mesopotamia, Roman architects perfected it and used it in buildings where it could stand on its own and support a great deal of weight. The first use of concrete by the Romans was in the town of Cosa sometime after 273 BCE. Ancient Roman concrete (opus caementicium) was a mixture of lime mortar, sand, water, and stones. The ancient builders placed these ingredients in wooden frames where it hardened and bonded to a facing of stones or (more frequently) bricks. When the framework was removed, the new wall was very strong with a rough surface of bricks or stones. This surface could be smoothed and faced with an attractive stucco or thin panels of marble or other colored stones called revetment. Concrete construction proved to be more flexible and less costly than building solid stone buildings. The materials were readily available and not difficult to transport. The wooden frames could be used more than once, allowing builders to work quickly and efficiently.

On return from campaigns in Greece, the general Sulla returned with what is probably the most well-known element of the early imperial period: the mosaic, a decoration of colorful chips of stone inset into cement. This tiling method took the empire by storm in the late first century and the second century and in the Roman home joined the well known mural in decorating floors, walls, and grottoes in geometric and pictorial designs.

Though most would consider concrete the Roman contribution most relevant to the modern world, the Empire's style of architecture, though no longer used with any great frequency, can still be seen throughout Europe and North America in the arches and domes of many governmental and religious buildings.