Isaak Argyros was born in Thrace around 1300-1310 and lived in Constantinople. As a monk, he took part in the religious controversies of Hesychasm and wrote treatises against Gregory Palamas. His scientific work is related to the fields of astronomy, arithmetic, trigonometry and geometry. He was also a disciple of Nikephoros Gregoras, whose work he continued. He wrote two treatises titled “Construction of New Tables” based on Ptolemy, as well as a treatise titled “On the Date of Easter”. The astronomical work of Argyros also included a treatise “On the Astrolabe”, based on that of Nicephorus Gregoras. He also wrote a treatise “On Geodesy”, which corrects the crude errors of the land surveyors. A number of astronomical (on Cleomedes, Theon of Alexandria) and geographical comments were attributed to Argyrus, as well as an edition of the Harmonics of Ptolemy. He also wrote comments in the first six books of Euclid's Elements. Apart from the theological works mentioned above, and his scientific output, he also wrote a treatise on poetic meters, and commentaries on Aristotle. His works were extensively used by his immediate successors. Conservative in his views, he remained faithful to the Ptolemaic tradition, despite making mention of the Persians in his Easter treatise. The only trace of innovation could be considered his correction of the length of the tropical year, although this does not appear in his astronomical tables. Argyros emerges as a unique Byzantine savant, trained in all scientific disciplines of the ancients, as well as in Theology and Philology, editing, and commenting the texts in the manuscripts. Until today, though, his interventions have not yet been precisely cataloged.