---
title: Arch of Janus
author: Mark Cartwright
source: https://www.worldhistory.org/article/593/arch-of-janus/
format: machine-readable-alternate
license: Creative Commons Attribution-NonCommercial-ShareAlike (https://creativecommons.org/licenses/by-nc-sa/4.0/)
updated: 1970-01-01
---
# Arch of Janus
_Authored by [Mark Cartwright](https://www.worldhistory.org/user/markzcartwright/)_
The Arch of [Janus](https://www.worldhistory.org/Janus/), erected in the 4th century CE, stands in the forum Boarium of [Rome](https://www.worldhistory.org/Rome/) and was most probably set up as a boundary-marker rather than a commemorative [triumphal arch](https://www.worldhistory.org/Triumphal_Arch/). The four-way marble arch stands over the Cloaca Maxima or Great Drain which ran down to the river Tiber.
[  Arch of Janus Mark Cartwright (CC BY-NC-SA) ](https://www.worldhistory.org/image/1371/arch-of-janus/ "Arch of Janus")The monument presents an imposing squat block of masonry and stands 16 m high and 12 m wide with an archway on each of its four sides. The [Roman](https://www.worldhistory.org/disambiguation/Roman/) Regionary Catalogues mention an 'Arch of the Deified [Constantine](https://www.worldhistory.org/disambiguation/Constantine/)' somewhere in the vicinity and some scholars have identified the Arch with that. The exact date of the arch's construction is also unknown but [pottery](https://www.worldhistory.org/pottery/) shards used in parts of the concrete vaults suggest a date some time in the 4th century CE. The marble blocks of the arch display evidence of having been previously used elsewhere.
Each pier of the arch has two rows of three niches, each topped by an elegantly carved semi-dome made to resemble a clam shell. It would seem likely that statues would have adorned these niches but, unfortunately, none survive. Small detached columns once flanked the niches but have also since been lost. The keystone at the apex of the central arch on the north side is carved to depict [Minerva](https://www.worldhistory.org/Minerva/), the keystone on the east side depicts [Roma](https://www.worldhistory.org/disambiguation/Roma/). Originally, the arch would have had an upper story, probably the standard rectangular shaped attic, although, a [pyramid](https://www.worldhistory.org/pyramid/) has also been suggested. There is also a staircase within the north-west pier which would have given access to this upper story and also leads to upper chambers within the pier itself.
[  Detail, Arch of Janus, Rome Mark Cartwright (CC BY-NC-SA) ](https://www.worldhistory.org/image/1372/detail-arch-of-janus-rome/ "Detail, Arch of Janus, Rome")The monument, like many other buildings from antiquity, suffered in later times, particularly in the Middle Ages when it was converted into a fortress. In 1830 CE a superstructure of brick and concrete was removed from the monument in the mistaken belief that this had been a part of the fortifications the Frangipani had added. The original iron pins which held together each block of marble were removed in the Middle Ages resulting in the ugly pock-marked look of the monument today. The arch has also suffered severe damage due to weathering and environmental pollution and now stands rather forlornly, fenced off and surrounded by modern residential buildings.
#### Editorial Review
This human-authored article has been reviewed by our editorial team before publication to ensure accuracy, reliability and adherence to academic standards in accordance with our [editorial policy](https://www.worldhistory.org/static/editorial-policy/).
## Bibliography
- [Amanda Claridge. *Rome.* Oxford University Press, USA, 2010.](https://www.worldhistory.org/books/0199546835/)
- [Claudia Costantino. *Roman Forum, Palatine & Colosseum.* Electa, Milan, 2010.](https://www.worldhistory.org/books/8837062028/)
- [Martin - Editor Henig. *A Handbook Of Roman Art - A Comprehensive Survey Of All The Arts Of The Roman World..* Cornell University Press, 1990.](https://www.worldhistory.org/books/B000LZDEXO/)
- [Mortimer Wheeler. *Roman Art and Architecture.* Thames & Hudson, 1985.](https://www.worldhistory.org/books/0500200211/)
## About the Author
Mark is WHE’s Publishing Director and has an MA in Political Philosophy (University of York). He is a full-time researcher, writer, historian and editor. Special interests include art, architecture and discovering the ideas that all civilizations share.
## Cite This Work
### APA
Cartwright, M. (2013, August 06). Arch of Janus. *World History Encyclopedia*.
### Chicago
Cartwright, Mark. "Arch of Janus." *World History Encyclopedia*, August 06, 2013. .
### MLA
Cartwright, Mark. "Arch of Janus." *World History Encyclopedia*, 06 Aug 2013, .
## License & Copyright
Submitted by [Mark Cartwright](https://www.worldhistory.org/user/markzcartwright/ "User Page: Mark Cartwright"), published on 06 August 2013. The copyright holder has published this content under the following license: [Creative Commons Attribution-NonCommercial-ShareAlike](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en). This license lets others remix, tweak, and build upon this content non-commercially, as long as they credit the author and license their new creations under the identical terms. When republishing on the web a hyperlink back to the original content source URL must be included. Please note that content linked from this page may have different licensing terms.