Imperial Architecture in Rome: From the Flavians through the Antonines

The Flavian Dynasty: Vespasian's Restitution and Physical Restoration

• Transition from Julio-Claudian Rule:     * The death of Nero was followed by a year of extreme turmoil and civil war ($69\,ce$).     * Four emperors ascended the throne in a little over a year: Galba, Otho, and Vitellius (each ruling only a matter of months) before they were dethroned and murdered.     * Vespasian, commander of the army in Palestine, was proclaimed emperor by his troops in $69\,ce$ at age $60$.

• Vespasian's Political and Architectural Strategy:     * Unlike the aristocratic Julio-Claudians, Vespasian was of humble, central Italian stock, known for deadpan jokes and self-effacing humor.     * His administration was efficient and parsimonious, acting as a remedy to the ruinous spending of the latter Julio-Claudians (specifically Nero).     * Political Message: Like Augustus, he presented himself as the emperor of "restitution," focusing on restoring the physical and moral fabric of Rome.

• Early Projects and Infrastructure:     * Temple of Capitoline Jupiter: Reconstructed after being burned in the war; Vespasian allegedly carried the first basket of debris on his back.     * Tabularium and Bronze Tablets: Restoration of the state archives and the recreation of some $3,000$ ancient bronze tablets recording Roman history that were lost in the Great Fire of $64\,ce$.     * Urban Overhaul: Reparation of streets, bridges, sewers, waterways, and granaries.     * Pomerium: The official and sacred boundary of the city was extended in $75\,ce$ for the first time since Claudius.     * Temple of Deified Claudius: Vespasian completed this temple (begun by Nero but abandoned) on the Caelian hill to associate himself with the more deserving Julio-Claudians.         * Structure: A cult temple on a raised terrace ($180 \times 200\,m$) with interconnected vaulted chambers.         * Style: The west façade features exaggerated rustication (bulging blocks against smooth edges) in a self-conscious imitation of Claudian masonry (e.g., Porta Maggiore).

The Forum of Peace (Templum Pacis)

• Thematic Significance: Established to celebrate the end of the internal war ($69\,ce$) and the victory over the Jewish uprising in Jerusalem attained by Titus in $71\,ce$.

• Architecture and Layout:     * Dedicated in $75\,ce$; located at the east end of the Forum of Augustus, separated by a street to the Subura district.     * Dimensions: A squarish enclosure measuring approximately $110 \times 105\,m$.     * Features: Paved partially in marble with a central clay area planted as a formal garden with canals and rows of trees.     * Temple Design: The temple of "Pax" was a rectangular hall at the center of the east side, not raised on a podium. It shared a common colonnaded frontage with the rest of the precinct.     * Function: Served as an "academy" or cultural center; displayed Greek masterpieces (including art moved from Nero's Domus Aurea) and spoils from Jerusalem (like the Ark of the Covenant).     * Forma Urbis Romae: The famous marble map of Rome was displayed on the south hall wall during the Severan age.

The Colosseum (Flavian Amphitheater)

• Site and Symbolism:     * Built over the Stagnum Neronis (artificial lake of Nero's Golden House), symbolically returning land taken for private luxury back to the public.     * Etymology: Known as the "Colosseum" due to its proximity to the Colossus of Nero, not its physical size.

• Structural Specifics:     * Dimensions: Elliptical form measuring roughly $188 \times 156\,m$ and $48.5\,m$ high.     * Capacity: Estimated at $45,000$ to $50,000$ spectators.     * Foundation: Ring-shaped concrete cut $9\text{--}12\,m$ deep.     * Exterior Tiers: Four levels of travertine. The first three levels utilize arches with engaged columns: Tuscan, Ionic, and Corinthian order. The fourth level is a blank wall with Corinthian pilasters and brackets for the velarium (canvas awning managed by Roman navy sailors).     * Interior Organization: $80$ radiating walls connected by sloping concrete barrel vaults. This "structural girdle" supported marble seating on the extrados ($outer surface$) of the vaults.     * Vomitaria: $76$ numbered gates spewing out spectators, allowing the building to empty in minutes.

• The Subterranean "City":     * A network of service corridors, cells, and mechanical elevators developed under Domitian.     * Used for caging wild animals and hoisting scenery through trap doors onto a floor made of heavy planks covered in sand to absorb blood.

• Social Hierarchy and Ideology:     * Seating Order: The Emperor in a special box; Senators and nobles on the pulvinar (podium); commoners (plebs) above; and women in the uppermost gallery.     * Acclamatio: The amphitheater allowed the populace a rare socio-political mechanism to express opinions and reach leaders during public assembly.

Titus and Domitian: Public Baths and Theatrical Architecture

• Baths of Titus ($80\,ce$):     * Located on the Oppian Hill; built in great haste to coincide with the Colosseum's inauguration.     * Design: "Small imperial type" with a north-south axis marked by a caldarium (south) and frigidarium (north) of approximately $23\,m$ span.     * Ludus Magnus: A gladiatorial training school situated east of the Colosseum with its own oval training arena and underground access to the main amphitheater.

• Domitian and Rabirius:     * Domitian (ruled $81\text{--}96\,ce$) was a "bad" son in the eyes of history but a proficient builder who recognized the talent of his chief architect, Rabirius.     * Arch of Titus: Single-opening arch of Pentelic marble over a concrete core with Composite capitals (Ionic volutes + Corinthian foliage).     * Temple of Deified Vespasian: Hexastyle temple squeezed against the Tabularium, unique for placing front steps between the columns to accommodate site restrictions.     * Forum Transitorium (Forum of Nerva):         * Created from the narrow Argiletum street ($45 \times 150\,m$).         * Utilized "pseudo-colonnades" (columns standing in front of walls) to create an illusion of space in a narrow corridor.         * Temple of Minerva: Dedicated to Domitian's favorite goddess; featured a frieze showing the myth of Arachne.

The Flavian Palace (Palatium)

• Design Philosophy: Rabirius moved away from the sprawling, linear Neronian villa model toward a vertical, urban, and layered architectonic complex.

• Domus Flavia (Official Wing):     * Aula Regia: A throne room with walls formatted like a "baroque" setting with niches and fluted columns. Debated roofing: either a $30.30\,m$ masonry vault or a timber-truss roof.     * Triclinium (Cenatio Iovis): Banqueting hall flanked by fountain courts with oval islands and scalloped pools.     * Maze Pool: An octagonal maze within a shallow basin located in the central peristyle.

• Domus Augustana (Quasi-Private Wing):     * Arranged in two levels, falling $11\,m$ toward the Circus Maximus.     * Pelta Court: A sunken courtyard with a pool featuring back-to-back semicircular segments resembling "pelta" shields.     * Stairway: A soaring, positive space wrapping around a long pool, connecting the two levels.

• The Garden Stadium: An elongated sunken garden ($160 \times 50\,m$) with a huge semicircular and coffered imperial box (exedra).

Trajan and Apollodorus of Damascus

• Trajan (98–117 ce): The first provincial emperor (born in Spain) known as Optimus Princeps.

• Public Works: Focused on standard of living: Aqua Traiana aqueduct, the expansion of the Via Appia into the Via Traiana, and the creation of a massive hexagonal harbor at Portus with a $700\,m$ distance across.

• Thermae of Trajan ($104\text{--}109\,ce$):     * Six times larger than Titus' baths; oriented $36^{\circ}$ southwest for maximum sun exposure.     * Established the mature "Imperial Bath" type: central frigidarium, axial natatio (pool), and internal palaestrae (exercise courts).

• The Forum of Trajan ($112\,ce$):     * Basilica Ulpia: Largest columnar hall in Rome ($170\,m$ total length with apses). Nave span of roughly $24\,m$ with double ambulatories.     * Column of Trajan: $100\,RF$ (Roman Feet) tall shaft ($39\,m$ total with base). Features a spiral relief $200\,m$ long depicting the Dacian Wars. The base contains a tomb chamber for Trajan's ashes.     * Markets of Trajan: A commercial district molded into the Quirinal Hill hillside with over $150$ shops.         * The Market Hall (Aula dei Mercati): A trapezoidal block with six cross-vaults springing over travertine brackets.         * Via Biberatica: The "pepper road" main shopping street with red-brown brick façades.

Hadrian: The Architect-Emperor

• Personality: Restless, flamboyant, and deeply appreciative of Greek culture (Graeculus). Favored an empire at peace within secure borders.

• The Pantheon ($118\text{--}128\,ce$):     * Architecture: A cylindrical rotunda grafted onto a columnar porch. Diameter and height both equal $43.30\,m$.     * The Dome: Constructed of concrete with graded aggregate (heaviest travertine at bottom, light volcanic slag at the top). Features $140$ coffers and a $9\,m$ diameter oculus as the sole light source.     * Authorship Controversy: Traditionally attributed to Hadrian, but some scholars cite Late Trajanic brick stamps as evidence for Apollodorus of Damascus being the original designer/patron.

• Temple of Venus and Roma: A huge decastyle dipteros (ten columns at end) of Greek style on a low platform, criticized by Apollodorus for being too "squat."

• Mausoleum of Hadrian (Castel Sant'Angelo):     * A square base ($87\,m$ side) with a tall cylindrical drum ($64\,m$ diameter).     * Linked to Campus Martius via the Pons Aelius bridge.

Hadrian's Villa at Tivoli

• Scope: A $300$-acre estate characterized by "clusters" of buildings rather than a single axis, utilizing water as a connective tapestry.

• Key Components:     * Poikele: A vast peristyle with a running track exactly one stade ($200\,m$) long.     * Small Baths: A masterwork of complex spatial geometry featuring an octagonal hall with undulating walls.     * Canopus: A scenic canal ($121 \times 18\,m$) terminating in a grotto nymphaeum (Serapeum) with a segmented "pumpkin" half-dome.     * Island Enclosure (Teatro Marittimo): A miniature "island villa" surrounded by a circular moat ($4.90\,m$ wide) and high walls ($44\,m$ external diameter) for the Emperor's solitude.     * Piazza d'Oro: A peristyle garden with a triclinium-nymphaeum featuring a sinuous, curving colonnade.

Architecture Under the Antonines

• Hadrianeum ($145\,ce$): Dedicated to deified Hadrian by Antoninus Pius. Features the first convex (pulvinated) frieze in Rome and reliefs of provinces dressed in native costume.

• Temple of Faustina and Antoninus Pius: Standard Roman hexastyle prostyle temple with green monolithic cipollino columns ($14\,m$ tall).

• Column of Marcus Aurelius ($180\text{--}193\,ce$): Modelled after Trajan's Column, it stands $100\,RF$ tall and depicts the bloody German Wars.

• Temple of Serapis: A "giant" temple on the Quirinal Hill with a twelve-column façade (unprecedented) and columns reaching nearly $20\,m$ in height.