Marcus Vitruvius Pollio (c. 90 - c. 20 BCE), better known simply as Vitruvius, was a Roman military engineer and architect who wrote De Architectura (On Architecture), a treatise which combines the history of ancient architecture and engineering with the author's personal experience and advice on the subject. He served as a military engineer and architect for Julius Caesar between 58 and 51 BCE and he personally visited Greece, Asia, North Africa, and Gaul. He was considered an expert on ballistics and he also built a basilica at Fanum Fortunae (modern Fano in Umbria, Italy) in c. 27 BCE. In De Architectura, written 30-20 BCE, Vitruvius gives a very personal account of ancient and contemporary architecture which draws on his own experience and on older works, especially by Greek writers such as Hermogenes of Alabanda, who wrote in the 2nd century BCE.