The Roman grid towns – together with the Jeffersonian cities in America – might qualify as the most prominent examples among this particular type of city layout. The origin of the Roman grid town is rather vague. The Roman writer Varro (116 – 27 BC) noted in his book ‘De lingua Latina’ (5.143) that the Romans founded their towns with ‘Etruscan ritual’, which could point to an influence of this ancient tribe on the northern slopes of the Apennines.
The Etruscan town of Marzabotto, some 27 kilometers SSW of Bologna (Italy) might be a point in favor of this conjecture. The colony probably dated from the late sixth century BC and has a rudimentary orthogonal pattern (GATES, 2003). The rectangular town-plan has streets crossing at right angles with blocks of houses (fig. 592). The place had a relatively short life because it was sacked in the fourth century BC by the Gaul and further occupation has been scanty.
Fig. 592 – Marzabotto is an Etruscan town with a grid pattern, which might have influenced later Roman city development.
A map of Marzabotto – Fig. 12 in: HAVERFIELD, F. (1913). Ancient Town-Planning. At the Clarendon Press, Oxford.
HAVERFIELD (1913; p. 62) did not believe that the Etruscan town plan was instrumental in the Roman art of town-planning. The latter – with its customs of the templum and the division in four quarters (see Ch. 18.104.22.168.; fig. 550) – is only properly documented about 200 BC. However, the layout of a Roman camp was, according to Haverfield, long known before the Greek historian Polybius (c. 203 – 120 BC) described it in words in the middle of the second century BC in his book ‘The Histories’.
The Roman army had developed a straightforward way of setting up camp when they were involved in their expansion wars. The four-fold principle was the guideline of the Roman approach to reality and its dealing with the practicalities of life. Four is a practical number: not too few and not too many. An encampment in a relative flat terrain was based on a distinct fourfold plan. The main streets were called cardo and decumanus and the four quadrants (or centuria, consisting of 4 x 25 blocks) were divided in a grid.
The foundation of colonial cities started in the second half of the Roman Republic (300 – 30 BC) under the same social and political circumstances as seen before in the Greek cultural domination during their period of colonization (from 750 – 500 BC). The growing urban densities at home resulted in a shortage of available land and food. Colonies had to absorb the excess population of the parent cities (GALANTAY, 1979). This process commenced nearby in Ostia, founded in the middle of the fourth century BC at the mouth of the Tiber. The colonia started as a military camp to control maritime and river traffic and had the standard features of two bisecting main streets.
The settlement of Cosa, situated at a hill near a good harbor some hundred and forty kilometers north of Rome, was founded as a colonia in 273 BC in territory conquered from the Etruscan city of Vulci. The city walls were about two kilometers in length and had eighteen towers and four gates (fig. 593). Inside the walls was a regular grid, proving that the Romans adopted to this design in an early age. The citadel, or Arx, was the highest point in the southern part of the city. A Temple of Jupiter (Capitolium) and a temple dedicated to Mater Matuta were included in its walls. The Temple of Jupiter was originally built after 241 BC and rebuilt around 150 BC.
Fig. 593 – The city plan of Cosa, a harbor town north of Rome, displays an early application of the grid layout in Roman colonial cities. The plan proves that the orthogonal design was deliberately applied in difficult terrain as a genuine ‘Italian’ endeavor.
The conquest of Spain (Hispania) in the second century BC was another typical expression of such needs of expansion. The town of Numantia (near Soria) resisted the Romans for a long time and reached the cult status of the Masada fortress in Israel (conquered by the Romans in 74 AD). Scipio Aemilianus Africanus (185 – 129 BC) – after having defeated Carthage in 146 BC – attacked the former Iron Age hill fort and fortress town of Numantia in the year 134 BC. The siege lasted eight months and ended with the suicide of most of the inhabitants in 133 BC. The town was destroyed and rebuilt as a Roman grid town (fig. 594).
Fig. 594 – The town of Numantia (near Soria, Spain) was conquered in 133 BC in the Roman expansion war and rebuilt as a grid town.
The wars of expansion led to garrison towns in occupied countries. Germany had Xanten – known as Colonia Ulpia Traiana – and Cologne, Colonia Claudia Ara Agrippinensium (CCAA). Austria featured the town of Carnuntum. Ljubljana (Laibach, Emona) was situated in Slovenia. Orange, in France, was called Colonia Iulia Secunda-norum Arausio. It was founded in 45 BC by discharged soldiers of Caesar’s Second Legion. Silchester in England and Lambaesis in Algeria proved the wide geographical distribution of this type of settlements. The veteran colonies in Italy itself – like Naples, Bologna, Parma and Piacenza, followed by Como, Pavia, Verona, Turin (fig. 595) and Aosta – have the grid pattern still preserved.
A complete summary of the Roman grid towns – in and outside Italy – is not sought after here. In stead, one typical example of ‘centuriatio’ is given as a representative of similar cities, which were built by the Romans. It will also be noted, that the term ‘grid town’ is a generalization, which does not pay credit to the individual differences between the towns, both in their foundation history, planning intentions and subsequent execution.
Fig. 595 – The old Roman city layout in Turin (Italy) is still visible in this map of 1844. Turin, known as Augusta Taurinorum, began around 28 BC as a ‘colonia’ founded by Augustus. The walls enclose an area of approximately 745 x 695 meters and had four main gates. The north and south gates are not in straight opposition, but it is not clear if this was the original plan.
The Algerian town of Timgad is probably the best-known example of a Roman colonial town. It exhibits a perfect archetype of a once thriving community (fig. 596). Emperor Trajan founded the colonia as Colonia Marciana Trajana Thamugas (Marciana in honor of Trajan’s sister) in 100 AD for his soldiers of the Third Legion, which were garrisoned in the neighboring fortress of Lambaesis (Lambessa). The number of veterans can hardly be more than four hundred and the first population must have been around two thousand (apart from slaves) (HAVERFIELD, 1913; p. 112).
The walled, but unfortified city was laid out in the usual rigid Roman grid pattern. The decumanus maximus and the cardo are still visible and a – partially restored – Corinthian colonnade lines the latter. The cardo terminated at the forum. An open-air theater, four major baths, a library, and the Capitoline Temple are the other key buildings. At the west end of the decumanus rises the twelve meters high Arch of Trajan, which was partially restored in 1900. The orientation of the city did not follow the four directions of the wind rose, but it was said (by dr. Barthel) that the street which joins the east and west gates was laid out to point to the sunrise on the eighteenth of September, the birthday of Trajan.
The city of Timgad enjoyed a peaceful existence for several centuries and became a center of Christian learning before the Vandals sacked it in the fifth century. The Byzantine general Solomon occupied the city in 535 AD and a brief re-population took place, until the Berbers demolished the place in the seventh century. Timgad (Thamugas) passed from history after the defeat of Gregorius, governor of Africa, by the Arabs in 647. The Scottish explorer James Bruce (1730 – 1794) visited Timgad in 1765 and made drawings of the monuments. He was followed in 1875 by Sir R. Lambert Playfair, the British consul general at Algiers and Professor Masqueray, who published a report on the state of the ruins.
Fig. 596 – The city of Timgad in Algeria is a classical example of a Roman colonial gridiron town, generated in the context and needs of an orderly military organization. All the fourfold elements of Roman castrametion and urban development are brought together here. Not shown are the later additions to the town, which did not follow any geometry. The city was founded around 100 AD, which coincides with the greatest geographical extension of the Roman Empire under Trajan (reigned from 98 – 117 AD).
The approximate position of the Roman grid cities will now be plotted in the context of the Roman cultural history-as-a-whole (fig. 597). The Etruscan town of Marzabotta is indicated on the CF-graph, but does not qualify in the Roman cultural period proper. The colonia of Ostia, on the other hand, is a genuine Roman settlement established in order to assure control of the port of Rome. It started ca 350 BC as a regular military fort (castrum) covering a rectangular area of just over two hectares. The two dissecting main streets led to four city gates and the settlement followed the grid plan. The town expanded later – in the second and first century BC – beyond its original confines to cover around sixty-four hectares around 80 BC (when new walls were built). Emperor Trajan added around 112 AD a hexagonal harbor next to Claudius’ port (GATES, 2003).
Fig. 597 – The CF-graph of the Roman cultural history gives the position of some of the grid cities mentioned in the text.
The harbor city of Cosa can be qualified as a true Republican town, with walls, a citadel, a forum and a grid plan. Its foundation (in 273 BC) was inspired by military and economic intentions (to block Etruscan access to the sea). It marked the beginning of a period of enormous geographical extension with prosperous new towns (colonies), connected with an ever improving infrastructure of roads and bridges.
The Via Appia (Appian Way) from Rome to Campania (Naples) was paved as early as the late fourth century BC. Many of the new towns, in particular in the frontier zones, started their existence as army camps and continued their rectangular design. Julius Caesar’s march into France (in 58 – 51 BC) marked the end of the Republican period, but also a new start of urban development. The Roman Empire started when Octavian adopted the title of Augustus in 27 BC. and the greatest extension of the Roman Empire was reached at the end of the first century AD.
The bulk of Roman grid cities, either inside Italy or outside in the newly acquired territories, is concentrated in the Third Quadrant of the Roman cultural history, i.e. in the period between 375 BC and 125 AD. Extensive city building continued – for instance, in the Hauran area of Syria (see fig. 513) in the second to fourth century AD. The city designs are more diverse in the Fourth Quadrant of the Roman cultural presence and some (like Serjilla, in the center of fig. 513, wrongly spelled as Serjibla) have no plan at all. Regional influences, like the Nabataean architecture in Jordan and Syria, might have prevented Roman dominance. A town like Shahba (Philippopolis), which was the birthplace of the Syrian Emperor Philip (ruled from 244 – 249 AD), was created to be a replica of Rome – with all the outward signs of a Roman city (temples, arches, baths, etc) – but the design was less concerned with an initial ‘military’ layout leading to a grid pattern.