Why Roman Architecture Developed & Flourished
The Italian mainland was rich in resources that could be used as building materials. The travertine hard stone and the Carrara white marble were readily available, as was clay for bricks and pozzolana sand and lava for concrete. Roman colonies in Greece, Spain, Gaul, Asia and North Africa supplied marbles, alabaster and other materials.
Unlike the Greeks, who seemed mainly interested in temple, theater and stadium architecture of comparatively small scale, the Romans had a penchant for imposing buildings and structures that would reflect the prestige, might and wealth of the Roman Empire.
Such buildings and structures, erected in every corner of the Empire, were also meant to serve as unifying symbols for Roman citizens.
Roman roads and bridges were needed to connect different parts of the the Empire. This facilitated governance of Roman territory as well as the expansion of the Empire.
Roman aqueducts were needed to supply water to the cities.
Roman cities served as administrative hubs throughout the Empire. The cities usually had a forum and a basilica at the center and a protective city wall.
Roman cities were crowded and it was necessary to address the issue of housing the urban population and maintaining order. The Romans built multi-storied tenement buildings known as insulae to house the middle and lower classes; the upper classes lived in city palaces and country villas.
Public places like the basilica, baths, libraries, temples and amphitheaters were created, respectively, to serve as administrative and public meeting places, to promote public hygiene, to pay homage to the Roman gods, to serve as a repository of knowledge, and to provide public entertainment in the form of gladiatorial combats, animal fights, dramatic performances, etc.
To decorate public places and residences, the Romans created a variety of mosaics and murals.
Triumphal arches were erected to commemorate Roman military victories.