In Italy very few buildings (especially churches) were constructed in only one particular style. Massive, expensive structures often took centuries to complete, during which time tastes changed and plans were altered.
Classical: Greeks & Romans
The Greeks from the 6th century B.C. to the 4th century A.D. settled Sicily and southern Italy, and left behind some of the best-preserved ancient temples in the world.
Even so, it was Rome that flourished magnificently in architecture, advancing in size and majesty far beyond the examples set by the Greeks. Much of this development was because of the discovery of a primitive form of concrete and the fine-tuning of the arch, which was used with a logic, rhythm, and ease never before seen.
Monumental buildings were erected, each an embodiment of the strength, power, and organization of the empire itself. Some of the best examples still stand today in Rome, notably Trajan's Forum, Caracalla's Baths, the Colosseum, and Hadrian's Pantheon.
Classical orders were simplified into types of column capitals, with the least ornate used on a building's ground level and the most ornate used on the top: Doric (a plain capital), Ionic (a capital with a scroll), and Corinthian (a capital with flowering acanthus leaves).
Three Roman cities have been preserved, with street plans and, in some cases, even buildings remaining intact: doomed Pompeii and its neighbor Herculaneum (both buried by Vesuvius's A.D. 79 eruption), and Rome's ancient seaport Ostia Antica.
Flourishing from A.D. 800 to 1300, Romanesque architecture took its inspiration and rounded arches from ancient Rome. Its architects concentrated on building large churches with wide aisles to accommodate the masses.
Modena's Duomo (12th c.) marks one of the earliest appearances of rounded arches, and its facade is covered with great Romanesque reliefs. Milan's Basilica di San Ambrogio (11th-12th c.) is festooned with the tiered loggias and arcades that became hallmarks of the Lombard Romanesque.
Pisa's Cathedral group (1153-1360s) is typical of the Pisan-Romanesque style, with stacked arcades of mismatched columns in the cathedral's facade (and wrapping around the famous Leaning Tower of Pisa) and blind arcading set with lozenges. Lucca's Cattedrale di San Martino and San Michele in Foro (11th-14th c.) are two more prime examples of the style.
By the late 12th century, engineering developments freed architecture from the heavy, thick walls of the Romanesque and allowed ceilings to soar, walls to thin, and windows to proliferate.
The Gothic style was characterized by cross vaults, flying buttresses, pointed arches, and stained-glass windows.
The only truly French-style Gothic church in Italy is Milan's massive Duomo and Baptistery (begun ca. 1386), a lacy festival of pinnacles, buttresses, and pointy arches. Siena's Duomo (1136-1382), though started in the late Romanesque, has enough Giovanni Pisano sculptures and pointy arches to be considered Gothic.
As in painting, Renaissance architectural rules from the 15th to the 17th centuries stressed proportion, order, classical inspiration, and mathematical precision to create unified, balanced structures. An architect, Filippo Brunelleschi, in the early 1400s, grasped the concept of "perspective" and provided artists with ground rules for creating the illusion of three dimensions on a flat surface.
One of the first great Renaissance architects was Florence's Filippo Brunelleschi (1377-1476). Among his masterpieces in Florence are the Basilica di Santa Croce's Pazzi Chapel (1442-46), decorated with Donatello roundels; the interior of the Basilica di San Lorenzo (1425-46); and, most famous, the ingenious dome capping Il Duomo (1420-46). Brunelleschi traveled to Rome and studied the Pantheon up close to unlock the engineering secrets of its vast dome to build his own.
Michelangelo (1475-1564) took up architecture late in life, designing Florence's Medici Laurentian Library (1524) and New Sacristy (1524-34), which houses the Medici Tombs at Basilica di San Lorenzo. In Rome, you can see his crowning glory, the soaring dome of St. Peter's Basilica, among other structures.
The fourth great High Renaissance architect was Andrea Palladio (1508-80), who worked in a classical mode of columns, porticoes, pediments, and other ancient temple-inspired features. His masterpieces include Villa Foscari and the great Villa Rotonda, both in the Veneto countryside around Vicenza.
Baroque & Rococo
More than any other movement, the baroque (17th-18th c.) aimed toward a seamless meshing of architecture and art. The stuccoes, sculptures, and paintings were all carefully designed to complement each other -- and the space itself -- to create a unified whole. Excessively complex and dripping with decorative tidbits, rococo is kind of a twisted version of the baroque.
The baroque flourished across Italy. Though relatively sedate, Carlo Maderno's facade and Bernini's sweeping elliptical colonnade for Rome's St. Peter's Square make one of Italy's most famous baroque assemblages. One of the quirkiest and most felicitous baroque styles flourished in the churches of the Apulian city Lecce. For the rococo -- more a decorative than architectural movement -- look no further than Rome's Spanish Steps (1726), by architect de Sanctis, or the Trevi Fountain (1762), by Salvi.
Neoclassical to Modern
As a backlash against the excesses of the baroque and rococo, architects began turning to the austere simplicity and grandeur of the classical age and inaugurated the neoclassical style by the middle of the 18th century. Their work was inspired by the rediscovery of Pompeii and other ancient sites.
The Industrial Age of the 19th century brought with it the first genteel shopping malls of glass and steel. The country's take on the early-20th-century Art Nouveau movement was called Liberty Style. Mussolini made a spirited attempt to bring back ancient Rome in what can only be called Fascist architecture. Since then, Italy has built mostly concrete-and-glass skyscrapers, like the rest of the world, although a few architects in the medium have stood out.
Of the neoclassical, Caserta's Royal Palace (1752-74), outside Naples, was a conscious attempt to create a Versailles for the Bourbon monarchs. The unbelievably huge (and almost universally derided) Vittorio Emanuele Monument (1884-1927) in Rome, which has been compared to a wedding cake or a Victorian typewriter.
Fascist architecture still infests corners of Italy. You can see it at its best in Rome's planned satellite community called EUR, which includes a multistory "square Colosseum" so funky that it has been featured in many a film and music video. The mid-20th century was dominated by Pier Luigi Nervi (1891-1979) and his reinforced concrete buildings, Florence's Giovanni Berta Stadium (1932), Rome's Palazzeto dello Sport stadium (1960), and Turin's Exposition Hall (1949).
A Glossary of Architectural Terms
Ambone -- A pulpit, either serpentine or simple in form, erected in an Italian church.
Apse -- The half-rounded extension behind the main altar of a church; Christian tradition dictates that it be placed at the eastern end of an Italian church, the side closest to Jerusalem.
Atrium -- A courtyard, open to the sky, in an ancient Roman house; the term also applies to the courtyard nearest the entrance of an early Christian church.
Baldacchino (also ciborium) -- A columned stone canopy, usually placed above the altar of a church; spelled in English baldachin or baldaquin.
Baptistery -- A separate building or a separate area in a church where the rite of baptism is held.
Basilica -- Any rectangular public building, usually divided into three aisles by rows of columns. In ancient Rome, this architectural form was frequently used for places of public assembly and law courts; later, Roman Christians adapted the form for many of their early churches.
Caldarium -- The steam room of a Roman bath.
Campanile -- A bell tower, often detached, of a church.
Capital -- The top of a column, often carved and usually categorized into one of three orders: Doric, Ionic, or Corinthian.
Castrum -- A carefully planned Roman military camp, whose rectangular form, straight streets, and systems of fortified gates became standardized throughout the Empire; modern cities that began as Roman camps and still more or less maintain their original forms include Chester (England), Barcelona (Spain), and such Italian cities as Lucca, Aosta, Como, Brescia, Florence, and Ancona.
Cavea -- The curved row of seats in a classical theater; the most prevalent shape was that of a semicircle.
Cella -- The sanctuary, or most sacred interior section, of a Roman pagan temple.
Chancel -- Section of a church containing the altar.
Cornice -- The decorative flange defining the uppermost part of a classical or neoclassical facade.
Cortile -- Courtyard or cloisters ringed with a gallery of arches or lintels set atop columns.
Crypt -- A church's main burial place, usually below the choir.
Cupola -- A dome.
Duomo -- Cathedral.
Forum -- The main square and principal gathering place of any Roman town, usually adorned with the city's most important temples and civic buildings.
Grotesques -- Carved and painted faces, deliberately ugly, used by everyone from the Etruscans to the architects of the Renaissance; they're especially amusing when set into fountains.
Hypogeum -- Subterranean burial chambers, usually of pre-Christian origins.
Loggia -- Roofed balcony or gallery.
Lozenge -- An elongated four-sided figure that, along with stripes, was one of the distinctive signs of the architecture of Pisa.
Narthex -- The anteroom, or enclosed porch, of a Christian church.
Nave -- The largest and longest section of a church, usually devoted to sheltering or seating worshipers and often divided by aisles.
Palazzo -- A palace or other important building.
Piano Nobile -- The main floor of a palazzo (sometimes the second floor).
Pietra Dura -- Richly ornate assemblage of semiprecious stones mounted on a flat decorative surface, perfected during the 1600s in Florence.
Pieve -- A parish church.
Portico -- A porch, usually crafted from wood or stone.
Pulvin -- A four-sided stone that serves as a substitute for the capital of a column, often decoratively carved, sometimes into biblical scenes.
Putti -- Plaster cherubs whose chubby forms often decorate the interiors of baroque chapels and churches.
Stucco -- Colored plaster composed of sand, powdered marble, water, and lime, either molded into statuary or applied in a thin concrete-like layer to the exterior of a building.
Telamone -- Structural column carved into a standing male form; female versions are called caryatids.
Thermae -- Roman baths.
Transenna -- Stone (usually marble) screen separating the altar area from the rest of an early Christian church.
Travertine -- The stone from which ancient and Renaissance Rome was built, it's known for its hardness, light coloring, and tendency to be pitted or flecked with black.
Tympanum -- The half-rounded space above the portal of a church, whose semicircular space usually showcases a sculpture.