Romaka Siddhanta

The Romaka Siddhanta (रोमकसिद्धान्त), literally "The Doctrine of the Romans", is one of the five siddhantas (doctrine or tradition) mentioned in Varahamihira's Panchasiddhantika which is an Indian astronomical treatise.

Romaka Siddhanta is based on the astronomical learning of the Byzantine Empire, also referred to as the Eastern Roman Empire.

Content
It follows the Yavanajataka ("Natal Astrology of the Yavana (Greek)") as an example of the transmission of Greek and Roman astronomical knowledge (especially the Alexandrian school) to India during the first centuries of our era.

It is the only one of all Indian astronomical works which is based on the tropical system. It was considered one of "The Five Astronomical Canons" in India in the 5th century.