Vitruvius-Architect!

Vitruvius Pollio was a Roman architect, engineer, and author of De architectura (On Architecture), a handbook for Roman Architects. Little is known of his life, but Vitruvius is thought to have dedicated hi works to Augustus, and thought to have been alive during Caesar's rule. The treatise was conceived after 27 BC. Vitruvius tells of the basilica he built in Fanum, now Fano.
De architectura was based on personal experience and from theoretical from Greek architects such as Hermogenes. The handbook details almost every aspect of architecture, but lacks, because it is based on Greek models, and Rome soon departs from Greek architecture as it becomes a world power. The treatise is divided into 10 books, and details city planning and architecture in general. Vitruvius wished to preserve the classical tradition for temples and public buildings, but could not, as Rome moved on to making it's own unique architectural styles.
Leonardo Da Vinci's "Vitruvian Man" is based on De architectura, which details proportions of the human body.

Picture: http://www.antient.org/temples_files/vitruvius.jpg