New light on the relationship between the Montecitorio Obelisk and Ara Pacis of Augustus

Bernard Frischer, John Pollini, Nicholas Cipolla, Giuseppina Capriotti, Jackie Murray, Molly Swetnam-Burland, Karl Galinsky, Chrystina Häuber, John Miller, Michele R. Salzman, John Fillwalk, Matthew R. Brennan

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


The article takes as its point of departure recent work [Frischer forthcoming] critiquing the theory of Edmund Buchner about the relationship of the gnomonical instrument known as the Horologium Augusti and the Ara Pacis Augustae. As a result of this critique, the Montecitorio Obelisk could be situated with greater precision on the map of the city. A computer simulation showed that Buchner erred in positing that the shadow of the Montecitorio Obelisk went into the center of the Ara Pacis on Augustus’ birthday. In this article, computer simulations are used to develop a post-Buchnerian interpretation of the relationship of the obelisk and altar. Over 230 hitherto unrecognized solar and shadow alignments are reported. The first part of the article defines four zones around the monuments where the solar and shadows observations were made. In the second part of the article, specialists interpret the significance of the annual solar and shadow spectacle from various points of view. The conclusion synthesizes the results, arguing that the monuments were intentionally aligned and situated in order to propagate the same message as the one inscribed on two sides of the Montecitorio Obelisk [CIL 6.702 = ILS 91]: that Augustus was a devoted worshipper of the sun god (Sol), who brings Rome victory in time of war, and prosperity in time of peace through his earthly representative, the emperor.

Original languageEnglish
Article number2
JournalStudies in Digital Heritage
Issue number1
StatePublished - Mar 23 2017

Bibliographical note

Publisher Copyright:
© 2017 SDH Open Access Journal


  • Ara Pacis Augustae
  • Archaeoastronomy
  • Horologium Augusti
  • Montecitorio Obelisk
  • Stellarium
  • Unity

ASJC Scopus subject areas

  • Classics
  • Archaeology
  • History
  • Museology


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