The Hellenistic period is characterized by migration of knowledge between Greek and Ancient Near Eastern civilizations. The facilitated communication led to great development in all fields of sciences. Generally speaking, we know of geographical and literary connections. However, the exact routes through which knowledge was transferred often remain unknown. In this presentation I will focus on one such junction. Seleucus of Seleucia is an enigmatic Babylonian astronomer, known only from Greek sources (Strabo, Geography 1. 1. 9; 3.5.9; 16.1.6; Plutarch, Platonic Questions VIII, 1, 1006 C; Aetios, Cosmology 2.1.7; Meteorology and the Earth 3.17.9) and one later Muslim-Persian source (al-Razi, Treatise on Metaphysics). From these scant testimonies we receive contradicting information about his place of origin, but despite his name he should probably be placed in Mesopotamia in proximity to the Persian Golf. Based upon the preserved testimonies, it seems I suggest that this Seleucus, on whom we know so little, was in fact an important vertex in the network of knowledge of the second century BCE, originating from the important Uruk family of astronomers, he read and wrote in Greek, developed theories based on both traditions, and spread his knowledge to central Hellenistic astronomers.

In Almagest XIII, Ptolemy presents his theory of planetary latitudes, including calculations of the relevant parameters and tables for computing that coordinate. As is well known, many of the parameters provided there are quite inaccurate, primarily due to the sensitive methods Ptolemy used to derive the final results from a set of unspecified observations. Some years later, in the Planetary Hypotheses, he introduced a modified version of the model that was significantly more accurate. Notably, he improved the values for the inclinations of the eccentres and epicycles, and the positions of Saturn’s nodes. However, unlike in the Almagest, he did not explain how he derived these improved values. This presentation focuses on the cases of the superior planets and seeks to explore the observational basis and geometrical methods Ptolemy may have used to arrive at these parameters in the Planetary Hypotheses.

This article concerns John Lydus’ On Celestial Signs, written in Constantinople around the mid-6th century CE. Lydus’ work is primarily the translation and compilation of earlier works that discuss the predictive value of astrometeorological and natural phenomena. Beyond antiquarian curiosity, Lydus advocates for the persisting usefulness of interpreting celestial and meteorological signs, and the enduring value of ancient knowledge.

Building upon scholarship that centres late antique and early medieval meteorological and astronomical knowledge, as well as work that concerns late antique encyclopaedic and antiquarian texts, this article examines Lydus’ On Celestial Signs for the way in which it utilises and repurposes ancient source material. The primary focus of this paper will be the way in which Lydus’ text discusses the health of the social body and more generally, how it connects celestial and meteorological phenomena to bodily experiences of health and illness.

Broadly, I suggest that Lydus’ On Celestial Signs operated in an adjacent vein to other literary genres exhibiting encyclopaedic tendencies in late antiquity. It was part of a broader imperial discourse that attempted to map out, totalise, and impose order upon the social body.