Vitruvius Marcus Vitruvius Pollio (; c. 80–70 BC – after c. 15 BC), commonly known as Vitruvius, was a Roman author, architect, civil engineer, and military engineer during the 1st century BC, known for his multi-volume work entitled De architectura. His discussion of perfect proportion in architecture and the human body led to the famous Renaissance drawing by Leonardo da Vinci of Vitruvian Man. He was also the one who, in 40 BCE, invented the idea that all buildings should have three attributes: , , and , meaning: strength, utility, and beauty. These principles were later adopted by the Romans. By his own description Vitruvius served as an artilleryman, the third class of arms in the military offices. He probably served as a senior officer of artillery in charge of doctores ballistarum (artillery experts) and libratores who actually operated the machines. Life and career Little is known about Vitruvius' life. Most inferences about him are extracted from his only surviving work De Architectura. Even his first name Marcus and his cognomen Pollio are uncertain. Marcus Cetius Faventinus writes of "Vitruvius Polio aliique auctores"; this can be read as "Vitruvius Polio, and others" or, less likely, as "Vitruvius, Polio, and others". An inscription in Verona, which names a Lucius Vitruvius Cordo, and an inscription from Thilbilis in North Africa, which names a Marcus Vitruvius Mamurra have been suggested as evidence that Vitruvius and Mamurra (who was a military praefectus fabrum under Julius Caesar) were from the same family; or were even the same individual. Neither association, however, is borne out by De Architectura (which Vitruvius dedicated to Augustus), nor by the little that is known of Mamurra. Vitruvius was a military engineer (praefectus fabrum), or a praefect architectus armamentarius of the apparitor status group (a branch of the Roman civil service). He is mentioned in Pliny the Elder's table of contents for Naturalis Historia (Natural History), in the heading for mosaic techniques. Frontinus refers to "Vitruvius the architect" in his late 1st-century work De aquaeductu. Likely born a free Roman citizen, by his own account, Vitruvius served in the Roman army under Caesar with the otherwise poorly identified Marcus Aurelius, Publius Minidius, and Gnaeus Cornelius. These names vary depending on the edition of De architectura. Publius Minidius is also written as Publius Numidicus and Publius Numidius, speculated as the same Publius Numisius inscribed on the Roman Theatre at Heraclea. As an army engineer he specialized in the construction of ballista and scorpio artillery war machines for sieges. It is speculated that Vitruvius served with Caesar's chief engineer Lucius Cornelius Balbus. The locations where he served can be reconstructed from, for example, descriptions of the building methods of various "foreign tribes". Although he describes places throughout De Architectura, he does not say he was present. His service likely included north Africa, Hispania, Gaul (including Aquitaine) and Pontus. To place the role of Vitruvius the military engineer in context, a description of "The Prefect of the camp" or army engineer is quoted here as given by Flavius Vegetius Renatus in The Military Institutions of the Romans: The Prefect of the camp, though inferior in rank to the [Prefect], had a post of no small importance. The position of the camp, the direction of the entrenchments, the inspection of the tents or huts of the soldiers and the baggage were comprehended in his province. His authority extended over the sick, and the physicians who had the care of them; and he regulated the expenses relative thereto. He had the charge of providing carriages, bathhouses and the proper tools for sawing and cutting wood, digging