Overview

Despite the technical developments of the Romans, which took their buildings far away from the basic Greek conception where columns were needed to support heavy beams and roofs, they were very reluctant to abandon the classical orders in formal public buildings, even though these had become essentially decorative.citation needed However, they did not feel entirely restricted by Greek aesthetic concerns and treated the orders with considerable freedom.citation needed

Innovation started in the 3rd or 2nd century BC with the development of Roman concrete as a readily available adjunct to, or substitute for, stone and brick. More daring buildings soon followed, with great pillars supporting broad arches and domes. 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.

Factors such as wealth and high population densities in cities forced the ancient Romans to discover new architectural solutions of their own. The use of vaults and arches, together with a sound knowledge of building materials, enabled them to achieve unprecedented successes in the construction of imposing infrastructure for public use. Examples include the aqueducts of Rome, the Baths of Diocletian and the Baths of Caracalla, the basilicas and Colosseum. These were reproduced at a smaller scale in most important towns and cities in the Empire. Some surviving structures are almost complete, such as the town walls of Lugo in Hispania Tarraconensis, now northern Spain. The administrative structure and wealth of the empire made possible very large projects even in locations remote from the main centers, as did the use of slave labor, both skilled and unskilled.

Especially under the empire, architecture often served a political function, demonstrating the power of the Roman state in general, and of specific individuals responsible for building. Roman architecture perhaps reached its peak in the reign of Hadrian, whose many achievements include rebuilding the Pantheon in its current form and leaving his mark on the landscape of northern Britain with Hadrian's Wall.

Originsedit

While borrowing much from the preceding Etruscan architecture, such as the use of hydraulics and the construction of arches, Roman prestige architecture remained firmly under the spell of Ancient Greek architecture and the classical orders. This came initially from Magna Graecia, the Greek colonies in southern Italy, and indirectly from Greek influence on the Etruscans, but after the Roman conquest of Greece directly from the best classical and Hellenistic examples in the Greek world.citation needed The influence is evident in many ways; for example, in the introduction and use of the triclinium in Roman villas as a place and manner of dining. Roman builders employed Greeks in many capacities, especially in the great boom in construction in the early Empire.citation needed

Roman Architectural Revolutionedit

The Roman Architectural Revolution, also known as the Concrete Revolution, was the widespread use in Roman architecture of the previously little-used architectural forms of the arch, vault, and dome. For the first time in history, their potential was fully exploited in the construction of a wide range of civil engineering structures, public buildings, and military facilities. These included amphitheatres, aqueducts, baths, bridges, circuses, dams, domes, harbours, temples, and theatres.

A crucial factor in this development, which saw a trend toward monumental architecture, was the invention of Roman concrete (opus caementicium), which led to the liberation of shapes from the dictates of the traditional materials of stone and brick.

These enabled the building of the many aqueducts throughout the empire, such as the Aqueduct of Segovia, the Pont du Gard, and the eleven aqueducts of Rome. The same concepts produced numerous bridges, some of which are still in daily use, for example the Puente Romano at Mérida in Spain, and the Pont Julien and the bridge at Vaison-la-Romaine, both in Provence, France.citation needed

The dome permitted construction of vaulted ceilings without crossbeams and made possible large covered public space such as public baths and basilicas, such as Hadrian's Pantheon, the Baths of Diocletian and the Baths of Caracalla, all in Rome.citation needed

The Romans first adopted the arch from the Etruscans and implemented it in their own building. The use of arches that spring directly from the tops of columns was a Roman development, seen from the 1st century AD, that was very widely adopted in medieval Western, Byzantine and Islamic architecture.citation needed

Domesedit

The Romans were the first builders in the history of architecture to realize the potential of domes for the creation of large and well-defined interior spaces. Domes were introduced in a number of Roman building types such as temples, thermae, palaces, mausolea and later also churches. Half-domes also became a favoured architectural element and were adopted as apses in Christian sacred architecture.

Monumental domes began to appear in the 1st century BC in Rome and the provinces around the Mediterranean Sea. Along with vaults, they gradually replaced the traditional post and lintel construction which makes use of the column and architrave. The construction of domes was greatly facilitated by the invention of concrete, a process which has been termed the Roman Architectural Revolution. Their enormous dimensions remained unsurpassed until the introduction of structural steel frames in the late 19th century (see List of the world's largest domes).