Caecilius is a character from the ancient Roman world, primarily known from the educational series of Latin textbooks called Cambridge Latin Course. He is depicted as a wealthy banker living in the city of Pompeii during the first century AD. His full name is Caecilius Iucundus, and he represents the typical Roman citizen of his time, showcasing aspects of daily life, family, and business. In the stories, Caecilius interacts with his family, including his wife Metella and son Marcus, as well as various slaves and friends. These narratives help students learn Latin while providing insights into Roman culture, social structure, and the economy of the period.