Little is known about his life. Nothing definite about his birth or origins. What little we know comes from sporadic testimony and his own comments scattered throughout the prefaces of the ten books that make up De architectura. Vitruvius' engineering and architectural skills were probably employed in a job as scriba armamentarius in the military corps of the apparitores, the technical personnel that worked for the political heads of the public administration. But some witnesses also place him in the water corps. A career that began under Caesar (100-44 B.C.) continued in the service of Augustus (63 B.C..-14 A.D.) during his second triumvirate, and ended in the first years of the Principate. De architectura was the fruit of a lifetime of practical experience in the field, a clear and essential manual, even in its expressive means, presumably written piecemeal, and has come down to us without any drawings or blueprints, which were omitted by the copyists and lost in the course of the manuscript tradition. Not a treatise for experts or initiates, but a text for complete and immediate use, concise and accessible to all, while also making claims for the professional dignity of the architect and of a specific culture comprising a complex of technical notions here being made available to anyone who needed them. He considered arithmetic, geometry and drawing indispensable tools of architecture, though not to the exclusion of acoustics when planning a theater, or astronomy for solar clocks, medicine for the purity of water, jurisprudence for the rights of servants, philosophy for moral rectitude in the practice of his craft. De architectura was innovative, not so much in its specific content as in its effort to organize a body of professional knowledge accumulated over centuries, up through the entire Hellenistic period. It is often an indirect source of texts of technical Greek culture that otherwise would have been lost, and in its time roused much attention and debate, and continued to enjoy great fortune, though with contrasting judgments, throughout the Middle Ages and the modern era.