Ancient Rome was a city of a wide range of shrines and temples dedicated to the numerous gods of the Roman religion. The general concept of religio was there for all to see, from the shrines dedicated to the gods of the household to the capitol of Jupiter Optimus Maximus. The vagaries of time and changes in faith have seen many of these temples and shrines become lost to the modern world, a sad fate in which they were destroyed, recycled or simply forgotten. One such example amongst those lost was the Temple of Ianus Geminus in Rome. Whilst the building itself may no longer stand, its function, location and appearance have all been preserved in other sources. These sources area mix of literary and numismatic (coin) elements, helping to create a greater interest in the temple. With the information from these sources, we are provided with a foundation for our modern understanding of this building which held a highly contested and unusual significance to the people of Rome.

Temple Origins

Within the various literature concerning the temple there have been many different cited origins. Perhaps the most widely known origin stems from Livy's Ab Urbe Condita (1.19) originating the temple with the Roman king Numa who famously boosted the religious nature of the Roman populace. Numa created the temple to serve as an indicator of war and peace, hoping to increase the respect held for both in doing so. Archaeologists such as Valentine Müller (1943) have made comparisons between archaeological and literary sources - such as the supposed foundation occurring under Romulus and Titus Tatius. The location for the temple is given to have been in the Forum Roma`num, which would place the temple in an area of some significance. Platner & Ashby (1929) in their topographical map of Rome place Ianus Geminus along the northern end of the forum. The problem faced by modern archaeologists is that the temple itself, like many of its kind, has been demolished; lost forever during the rise of Christianity, although this may not be entirely accurate. Not long after Ianus Geminus was demolished, it had been largely replaced by the larger Ianus Quadrifons in the Forum Nervae. This newer, and far grander temple resulted in the rendering of the original to a much lower significance. What is known of Ianus Geminus' location is that it stood near the end of the Argiletum one of the main thoroughfares to the Forum Romanum. The map of Republican Rome by William Shepherd (1929) places the temple within sight of the Comitium and the Rostra. Such a position, near some of the most important governmental areas of Rome, indicates the potential for the temple to serve as a useful political symbol. However, when referring to Shepherd's map of Imperial Rome, the temple has ceased to exist in the Forum Romanum. It was replaced instead by parts of the Forum Nervae and the Basilica Aemilia. There is no record of the temple ever being rebuilt, though a temple of similar design and purpose is mentioned by Procopius (Gothic Wars 5.25).

What was it for?

The purpose of the temple is described in various ways depending on the author of the literature. The most commonly accepted, and what would have been the most visible purpose, was to serve as a physical representation of whether the Roman state was at peace or war (index pacis bellique). This purpose is attributed to the well-known Roman historians: Livy, Plutarch and Suetonius among several others. Perhaps one of the more important literary explanations of the function of the temple, can be found in the autobiography Res Gestae Divi Augusti. The closing of the gates of Ianus Geminus is listed amongst the greatest achievements of Augustus' life. The importance of this may undoubtedly be linked to the infrequent nature of this event. In point of fact, prior to its multiple closures by Augustus, Livy (1.19) mentions only two other recorded closings of the temple - first under King Numa and secondly at the end of the Second Punic War. This makes the fact that it is recorded that Augustus closed the gates thrice an even more remarkable feat. Discussion of the temples purpose was not however limited to historians - with Ianus Geminus featuring within the works of several poets as well. The temple being significant enough to not be overlooked by numerous poets speaks volumes to the familiarity with the temple held by the general populace. With that in mind however, the poets who featured the temple did not necessarily agree upon the function of the gates. With a differing of opinions centred around whether the gates trapped peace or war inside. The poets Horace and Ovid both maintained in their works that pax (peace) was to be kept and protected within the gates away from harm. Whereas, Virgil wrote that bellum (war) was held imprisoned within the gates of the temple - held in bondage until it was able to break free and afflict the Roman world again.

But what did it look like?

Just because the temple no longer stands, does not mean we cannot know what it looked like. One written description is the previously mentioned description by Procopius (5.25), written much later wherein the temple is made entirely from bronze and stood five cubits (2.28m) high. Whilst this description is helpful, it is somewhat basic in detail. There are a number of sources which allow us to look upon an image of the temple. This is thanks to the existence of its image upon a series of gold (aureus) and bronze (sestertius) coins, produced by the Emperor Nero. The coins were all created to commemorate the closing of the temple gates under Nero - serving as an effective means of propaganda. Whilst a commonly known fact being that coins have two sides, often their official names are unknown. These are referred to as the obverse (heads) and reverse (tails) sides. Upon the reverse side of these coins, a presumably large archway is shown sealed by an ornate gate. Around this, is the declaration that the temple had been closed by the emperor. The golden aurei are dated by the Online Coins of the Roman Empire (OCRE) as to having been produced between 64-66AD. One notable detail for the aurei depiction of Ianus Geminus, is that the arch itself appears to be generally lacking in any outward signs of decoration. The majority of the examples show the temple as being made of columns with an archway atop. The arch above the gates is depicted as being somewhat plain - lacking even a frieze as is often associated with ancient architecture. Instead the depiction is that the archway atop the columns is decorated only with a simple lip. Two of the existing coins however, differ in that they depict the temple as a singular smooth edifice. Whether this is due to wear or a regional mint variation is unknown. The gates of Ianus Geminus are the feature so commonly referred to in the literature that are depicted remarkably consistent across the collection. Each depiction showing an eight panelled gate, with the only variation being the level of detail on the bars of each gate. The sestertius produced over greater time (approximately 62-68AD) can be used to identify further details. The sestertii present details of the non-gated side of the temple revealing a grated window upon the left side, whilst also showing a decorative garland over the gate itself. Interestingly, unlike the coins on the OCRE website, those found in the work by Müller shows some frieze work along the side of the temple. The fact that the coins were all created to celebrate the closing of the gates is present within the embossed Latin upon the coins. This helps to create a link between the literary importance of the event with an actual physical object. Coins such as these aurei and sestertii, are extremely valuable sources to call upon as they preserve not only images and symbols, but frequently also the cultural significance too. It is for reasons such as these that numismatics is an extremely worthwhile study.


The story of Ianus Geminus is one shared by much of the old Rome, lost to us through the unending march of time. Still, through its presence in literature and upon the aurei and the sestersii of Nero it has been preserved at least in spirit. The study of Ianus Geminus not only presents an interesting view point into some of the more obscure aspects of Roman religion, it also serves to help keep the traditions of the past from being forgotten. It is through our connections to the past, and knowledge of the traditions long since faded, that help us to not only understand the people of the past but ourselves as well. After all history isn't just words on a page, it is the story of us.

Guide to Further Reading:

Livy, Ab Urbe Condita. (1.19)

Plutarch, The Life of Numa. (20.1-2)

Suetonius, Divus Augustus.(22.1).

Augustus, Res Gestae Divi Augusti (13)

Lendering, J. Temple of Janus



Claridge, A., 2010. Rome: An Oxford Archaeological Guide. Oxford University Press.

Ely, T., 2003. The Gods of Greece and Rome. New York.

Green, S.J., 2000. "Multiple Interpretation of the Opening and Closing of the Temple of Janus: A Misunderstanding of Ovid "Fasti" 1.281." Mnemosyne 53, pp. 302-309.

Grout, J., 2019. The Temple of Janus (Janus Geminus), viewed 8 May 2019

Hjort, C.L., 2009. Res Public Constituta: Actium, Apollo and the Accomplishment of the Triumviral Assignment.

Müller, V., 1943. 'The Shrine of Janus Geminus in Rome' American Journal of Archaeology 47, pp. 437-440.

Platner, S.B., 1929. Janus Geminus in T Ashby (ed.) A Topographical Dictionary of Ancient Rome.

Syme, R., 1979. "Problems about Janus", The American Journal of Philology 100, pp. 188-212.

Townend, G.B., 1980. "Tacitus, Suetonius and the Temple of Janus", Hermes 108, pp. 233-242.


Cassius Dio, Roman History

Book 51-55:

Horace, Odes (Kline, A.S. trans.)

Book 4:

Livy, Ad Urbe Condita (Heinemann, W. trans.)

Ovid, Fasti (Frazer, J.G. trans.)

Plutarch, The Life of Numa (Perrin, B. trans.)

Volume 1:

Suetonius, The Lives of the Twelve Caesars (Rolfe, J.C. trans.)

Divus Augustus:

Divus Vespasian:

Tacitus, Annals (Jackson, J. trans.)

Virgil, Aeneid (Williams, T.C. trans.)

Lee Treadwell

Lee Treadwell resides in Brisbane, Australia. I am currently completing my second university degree which is a bachelor of Ancient History through Macquarie University. The ancient Romans appeal to many of Lee's interests as their society has numerous similarities to our own.