509 BCE - 400 CE

Roman architecture originated in ancient Rome during the Roman Republic and later the Roman Empire. It can be divided into several  periods . Greek and Etruscan architectural styles heavily influenced it, but it evolved to reflect the changing needs of Roman society. 

Roman architecture has had a lasting impact on Western architecture and design. Many of the features and techniques developed by the Romans, such as arches, vaults, and concrete, are still used in construction today. Roman architecture also reflects the values and priorities of Roman society, such as their emphasis on civic infrastructure and their desire for grandeur and spectacle.
Important Features
Arches and Vaults
The arch, which was known to the ancient Greeks, was refined and perfected by the Romans. The arches allowed architects to construct larger and more complex structures like bridges, open spaces, aqueducts, and monuments that were both functional and beautiful.

The vault, essentially an extension of the arch, allowed for even larger spaces, and it made possible the construction of structures such as aqueducts, which were essential for supplying water to Roman cities.
The Romans were the first to use concrete extensively in their buildings, and they developed new techniques and formulas that allowed for faster and more efficient construction. Roman concrete was made from a combination of lime, volcanic ash, and small stones or gravel, and it was particularly well-suited for construction in wet or humid environments. Using concrete allowed the creation of intricate architectural details, such as ornate carvings and decorative elements.
The Romans used columns for both support and decoration. They continued the order types developed from Greek and developed Tuscan and Composite orders.

Tuscan order is simple and sturdy with a plain column shaft, a simple base, and a plain capital. It was developed in ancient Rome during the late Republican period and was commonly used in military structures, agricultural buildings, and rural villas.

Composite order is a late Roman and Renaissance architectural order that combines elements of the Ionic and Corinthian orders. Characterized by a tall column with a decorative capital that features acanthus leaves and scrolls. It is considered to be the most ornate of the classical orders.
Emphasis on Function
Roman architecture was beautiful and functional, with buildings designed to serve a specific purpose, whether a temple, public bath, or amphitheater.