The earliest surviving written work on the subject of architecture is De architectura, by the Roman architect <answer>Vitruvius</answer> in the early 1st century AD. According to <answer>Vitruvius</answer>, a good building should satisfy the three principles of firmitas, utilitas, venustas, commonly known by the original translation – firmness, commodity and delight. An equivalent in modern English would be:
Who was the author of  De architectura?
Vitruvius