Pomerium – new discovery

On 17 July 2021, an important and rare discovery was made during archaeological works carried out near the recently restored Mausoleum of Augustus in the Piazza Augusto Imperatore, just off the Via del Corso in Rome. A sizable travertine block (pomerium cippus) was unearthed, which defined the sacred boundary (pomerium) of Rome extended by Emperor Claudius in 49 AD. Although the discovered block is only partially preserved, with he censorial power of the the ruler (line 6) and a final formula: 

[au]ctis populi R[omani] / finibus, pomerium / ampliavit terminavitque 

(lines 7 – 9) 

linking this inscription to the activities of Claudius and similar cippi is most reasonable.

Why is the recent discovery in Rome so unique and of such a great significance?

Moment odkrycia pomerium © Sovrintendenza Capitolina ai Beni Culturali
Discovery of the pomerium
© Sovrintendenza Capitolina ai Beni Culturali

The sacred significance of the pomerium 

The Pomerium held a special place in the political culture of Rome and other Latin cities. According to Roman tradition, it was Romulus who ploughed  the first furrow, as a boundary, an important ritual for the foundation of the City. The pomerium had above all a sacral and ritual dimension, and the space (ager effatus) it delimized was consecrated by the “augurs of the Roman people” (augures populi Romani) (Gell. 13,14,1). By means of the pomerium, the urban space was under special auspices (auspicia urbana). Neither cultivation of land nor erection of buildings was allowed on this sacred strip of land or in its immediate vicinity. It was also forbidden to bury the dead within the pomerium (during the Republic the only exception was the burial of particularly meritorious persons (summi viri), and during the Empire the first ruler to be buried within the pomerium, or more precisely at the base of his column, was Trajan). In ancient historiography it was held that temples and places of worship dedicated to deities of foreign origin could not be located within the pomerium. However, Adam Ziółkowski in his numerous works disproved this erroneous thesis.

Boundary between civil and military power

The sacred strip of land marked a kind of border between civil power (imperium domi) and military power (imperium militiae). Within the boundaries of the pomerium (intra pomerium), the king, and later republican magistrates, exercised their authority, but without military powers because there was a ban on carrying arms within the borders of the pomerium. Therefore, military commanders, wishing to cross the sacred frontier, first had to renounce their command (imperium). The only exceptions were the triumphalists, who, together with their soldiers, could cross the pomerium, but on the condition that they received the consent of the senate. Outside the pomerium (extra pomerium) centurial assemblies (comitia centuriata), were held also originally of a military nature. In the monarchic period the king had the right to move the pomerium, and in the republican period leaders could expand the borders of the state as a result of wars (Gell. 13,14,3). This power was certainly exercised by Sulla and perhaps by Caesar as well. During the imperial period, the position of the emperor was unique, and the military power he held on the basis of imperium proconsulare maius quam (in relation to all governors and military commanders) did not have to be renewed each time the emperor left Rome and crossed the pomerium. Besides, during the principate, only the emperors Claudius and Vespasian with Titus extended the pomerium by virtue of the ius proferendi pomerii (Augustus’ extension of the pomerium is uncertain – the ruler himself did not mention it in the Res Gestae, nor is it mentioned in the Lex de Imperio Vespasiani).

Moment odkrycia pomerium © Sovrintendenza Capitolina ai Beni Culturali
Discovery of the pomerium
© Sovrintendenza Capitolina ai Beni Culturali

The boundaries of the Roman pomerium

The pomerium, whose course more or less coincided with that of the City, began at the Forum Boarium and initially included the Palatine Hill. According to Titus Livius and Aulus Gellius, by Titus Tatius the sacred boundary was extended to the Capitol Hill, and through the actions of Servius Tullius to the Quirinal, the Viminale and the Esquiline Hills. For a long time, the “ominous” Aventine and the “military” Campus Martius quarters were outside the pomerium. It was only on the initiative of Claudius that the southern part of the Campus Martius and, according to Aulus Gellius, the Aventine were incorporated into the pomerium (Gell. 13,14,7):

Aventinum antea, sicuti diximus, extra pomerium exclusum, post auctore divo Claudio receptum et intra pomerii fines observatum

[… the Aventine was, as we have said, excluded from the pomerium, but afterwards by the authority of the deified Claudius it was admitted and honoured with a place within the limits of the pomerium]

(transl.J. C. Rolfe)

Claudius, first emperor to extend pomerium

So far, the fact that Claudius extended the boundaries of the pomerium has only been mentioned by three stone blocks – the boundary stones (pomerium cippi) from Rome – CIL VI 1231a-c, VI 31537 a-d, whose main text (in fronte) reads: 

Ti(berius) Claudius / Drusi f(ilius) Caisar / Aug(ustus) Germanicus, / pont(ifex) max(imus), trib(unicia) pot(estate) / V̅I̅I̅I̅I̅I̅, imp(erator) X̅V̅I̅, co(n)s(ul) I̅I̅̅̅II̅, / censor, p(ater) p(atriae), / auctis populi Romani / finibus, pomerium / amplia((v))it termina((v))itq(ue) 

[Tiberius Claudius, son of Drusus, Caesar, Augustus, Germanicus, chief pontiff, with tribunician power for the ninth time, acclaimed imperator sixteen times, consul for the fourth time, censor, father of the fatherland, in consequence of the enlargement of the boundaries of the Roman people, expanded and separated the boundaries of pomerium]

(transl. K.Kłodziński)

Jeden z kamieni granicznych (cippus)cesarza Klaudiusza, który wyznaczał przedłużenie świętego obwodu miasta Rzymu (pomerium). Przechowywany w Watykanie pod numerem inwentarzowym 9268. Pismo Klaudiusza (odwrócona digamma, tutaj w kolorze czerwonym – zmodyfikowany obraz cyfrowy) zapisuje spółgłoskę V w ampliavit i terminavit. CIL 06, 01231c autor: P. Tribhou (opublikowano na licencji CC BY-SA 4.0, via Wikimedia Commons)
Cippus of the pomerium extended by the emperor Claudius, one of the boundary points that marked the extension of the sacred perimeter of the city of Rome. It is held in the Vatican under inventory number 9268, Claudius’ script (inverted digamma, here in red – modified digital image) records the consonant V in ampliavit and terminavit. CIL 06, 01231c. 
author: P. Tribhou
(Published under CC BY SA 4.0, via Wikimedia Commons)

In addition, this fact is mentioned in narrative sources (the aforementioned commentary of Aulus Gellius and the mention of Tacitus – Ann. 12,23,2) and in one source of a juridical nature, engraved on a bronze tablet, which is now kept in the Capitoline Museum – the Lex de Imperio Vespasiani. Clause V reads: 

utique ei fines pomerii proferre, promovere, cum ex re publica censebit esse liceat, ita uti licuit Ti. Claudio Caesari Aug(usto) Germanico)

[and that he shall be allowed to advance (and/or) move forward the boundaries of the pomerium when he thinks it useful for the State, just as was allowed to (the emperor Claudius)]

(transl. A.E. Gordon)

Brązowa tablica z Lex de Imperio Vespasiani, znajdująca się w Muzeum Kapitolińskim © J. L. Bernardes Ribeiro (opublikowano na licencji CC BY-SA 4.0, via Wikimedia Commons)
Bronze plaque Lex de Imperio Vespasiani, located in the Capitoline Museum
© J. L. Bernardes Ribeiro
(Published under CC BY SA 4.0, via Wikimedia Commons)

What made Claudius the first Roman emperor to return to the ritual of widening the pomerium?  Perhaps the ruler, particularly interested in Etruscan traditions and rituals (Suet., Claudius 42), decided on the procedure of widening the pomerium, which, like his triumphal arch on the Via Flaminia erected in 51-52, was intended to commemorate the conquest of Britain and victory over the enemy. The latter was the sine qua non for the extension of the pomerium.

Information about the discovery of the pomerium was published by Sovra Intendenza Capitolina ai Beni Culturali on FB, 17.07.2021

This article may be freely reprinted with photographs with licences, with reference to the source 

Author: Karol Kłodziński – doctor, historian of antiquity and epigraphist, assistant professor at the Department of Ancient History of the University of Gdańsk. He specialises in the history of the early Roman Empire, especially Roman Africa.



Translation and editing: J.M.C.

Proofreading: Daniel Viktor Takacs


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