Vitruvius (c 80–70 BC – after c 15 BC) was a Roman architect and engineer during the 1st century BC, known for his multi-volume work titled De architectura. As the only treatise on architecture to survive from antiquity, it has been regarded since the Renaissance as the first book on architectural theory, as well as a major source on the canon of classical architecture. It is not clear to what extent his contemporaries regarded his book as original or important. He states that all buildings should have three attributes: firmitas, utilitas, and venustas ("strength", "utility", and "beauty"), principles reflected in much Ancient Roman architecture. His discussion of perfect proportion in architecture and the human body led to the famous Renaissance drawing of the Vitruvian Man by Leonardo da Vinci. Little is known about Vitruvius' life, but by his own description he served as an artilleryman, the third class of arms in the Roman 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. As an army engineer he specialized in the construction of ballista and scorpio artillery war machines for sieges. It is possible that Vitruvius served with Julius Caesar's chief engineer Lucius Cornelius Balbus.
