a. d. viiii Kalendas Octobres, dies natalis Augusti. Some Considerations on the Astronomical Orientation of Roman Cologne and the Imperial Cult

Abstract

A key factor in planning and orienting towns in the Roman world, and in particular in Augustan towns, was cosmology. The application of cosmological criteria in these towns, associated with specific political and religious principles of the principate of Augustus, has been already identified in Italia, Gallia, and Hispania. In this article we examine the orientation of the Roman town of Ara Ubiorum (present day Cologne) that could be related with the dies natalis Augusti. Based on these results, such a relation could have been deliberately sought by Roman and Ubian authorities to connect the newly founded town, where there was an ara of the Imperial cult probably consecrated to Rome and Augustus, with Augustus, who was identified with Apollo-Sol.