Vitruvius

Marcus Vitruvius Pollio; his date of birth, around 80 BC and date of death, after 15 BC, are uncertain.
After retiring from public life and obtaining a pension from Augustus, he devoted himself to drafting the treatise De Architectura, at the very point in time in Rome when Augustus was undertaking a building development program.
Vitruvius, who is considered one of the most eminent theorists of architecture, was active in the second half of the 1st century BC. He was in charge of supervising war machines for Julius Caesar then worked as an architect and engineer on behalf of Augustus.