Concrete—a mixture of lime, volcanic ash, stones,
a binding agent, and water—had been in use on a minor
scale in Mesopotamia, but Roman architects perfected the
material. Concrete had advantages over previous architec-
tural materials, such as cut stone, in that it was exceedingly
strong and fl exible and was faster and cheaper to construct.
Th e Romans’ fi rst use of concrete dates to the late third
century b.c.e. Concrete allowed Roman architects to im-
prove upon a feature that had been used by the Greeks and
Etruscans: the arch. Th e arch is a highly stable structure
that transmits and bears weight very eff ectively. Arches can
accommodate a wider span than more traditional architec-
ture, which uses simple vertical and horizontal supports,
and the strength of concrete allowed for even wider spans.
Th e use of poured and shaped concrete to create arches
imparted a greater fl exibility of form as well. When arches
are extended, they create a barrel vault, like a semicylindri-
cal ceiling over a corridor.
Roman architects used concrete and the structures of the
arch and barrel vault to create new types of buildings. Th e
Sanctuary of Fortuna Primigenia at Palestrina in central Italy
is an early example of the creative and complex use of con-
crete vaults. Th e Pantheon in Rome, however, is perhaps the
most spectacular example of concrete construction. It was the
largest dome in the world until modern times. Th e Pantheon
survives almost completely intact, allowing visitors to gain an
exceptional sense of occupying an ancient space.
Although visitors to Rome and other ancient Roman cit-
ies in modern times see large sections of brick-faced concrete
walls that still stand, in antiquity these walls were frequently
covered with other materials, usually to give a richer appear-
ance. Stucco was oft en employed to cover the walls and could
be enhanced with thin layers of the fi ne plaster that was a
suitable surface for fresco painting. Both interior and exterior
walls could be plastered and painted. In more costly build-
ings, thin slabs of marble and other stones were used to cover
the concrete walls and therefore give the illusion that the en-
tire building was made of more expensive materials. White
marble was particularly popular for these panels, probably
because of the associations with more ancient and venerable
Greek buildings (which were actually made of solid marble in
many cases). Th e emperor Augustus is said to have boasted
that he transformed the city of Rome from a brick one to one
made of marble. Th is statement is partly true, since a great
many buildings were constructed in the city during Augus-
tus’s reign, frequently faced in white marble.
Colored marble was also popular for revetment panels
(decorative think slabs of stone) as well as entire columns and
pavements for fl oors. Th ese stones came from all corners of
the Roman Empire. Yellow stone veined with purple came
from Tunisia, green “serpentino” from southern Greece, red-
purple porphyry from Egypt, and the Phrygian white and
purple stone from what is now Turkey. Th ese colored stones,
in combination with glass and terra-cotta, could also be used
in small cubes, or tesserae, to make mosaics. Mosaics were
used as beautiful and durable fl oor coverings in private homes
and public buildings alike.ROMAN TEMPLES
Th e Romans most frequently worshipped their gods and god-
desses at temples. Roman cities were full of small and large
temples, which could also be dedicated to deifi ed emperors.
Most Roman temples were rectangular in plan; stood on a
high, stepped podium; and had one entrance at the front of
the building. A columned porch, topped by a pitched roof
(two sided and sloped) and pediment (the triangular section
just below a sloped roof, which sometimes contained sculp-
tural decoration), drew attention to the doorway. Th is is a
departure from the design of Greek temples, which typically
had colonnades (rows of supporting columns) along all four
sides, creating the illusion that no particular side was more
important than the others. Th e interiors of Roman temples
were occupied by statues of a deity as well as expensive gift s
that had been dedicated to the god or goddess. Some temples
were round in plan, also with a single entrance.
Th e Pantheon, constructed between 118 and 125 c.e.,
is the quintessential example of this kind of temple. Dedi-
cated to the 12 major Roman gods, the Pantheon is entered
through an impressive porch supported by enormous gran-
ite columns. Th e domed interior of the Pantheon alludes
to the canopy of the heavens and the orb of the world. In
the eastern part of the empire, especially aft er the second
century c.e., temple design became even more innovative.
Th e Temple of Venus at Baalbek (in modern-day Lebanon)
combines traditional aspects such as the high podium and
single entrance with a scalloped roofl ine and unique fi ve-
sided Corinthian column capitals.THE FORUM
Every Roman city had at its heart a forum. Th is was a place
for commercial, legal, political, and religious activity. A fo-
rum was essentially an open plaza, usually in the center of
a town. Th e open space was usually a rectangle marked by
colonnades or porticoes (covered entrances or walkways) on
three sides, with a major temple occupying one of the short
sides of the plaza. Th e forum was frequently decorated with
commemorative statues of military and political leaders and
other historic monuments. Arches, sometimes celebrating
military triumphs, could stand as monumental portals into
the forum. Arches celebrating the various victories of the em-
perors Augustus, Tiberius, and Septimius Severus stood in
the main forum in Rome. Porticoes provided shade for visi-
tors to the forum, who met friends and business associates
there for meetings. Administrative and political buildings
like the Senate house and record building were also located in
the main forum of a city.
Basilicas were multipurpose buildings common in the
Roman forum. A basilica was usually a long and narrow
rectangular structure with a wide central aisle and narrow
side aisles separated by rows of columns. Magistrates andarchitecture: Rome 79