In Roman architectural practice, capitals are briefly treated in their proper context among the detailing proper to each of the "Orders", in the only complete architectural textbook to have survived from classical times, the "De architectura", by Marcus Vitruvius Pollio, better known as Vitruvius, dedicated to the emperor Augustus. The various orders are discussed in Vitruvius' books iii and iv. Vitruvius describes Roman practice in a practical fashion. He gives some tales about the invention of each of the orders, but he does not give a hard and fast set of canonical rules for the execution of capitals.