Lucius Junius Moderatus Columella (/ˌkɒljəˈmɛlə/; 4 – c. 70 AD) is the most important writer on agriculture of the Roman empire. Little is known of his life. He was probably born in Gades, Hispania Baetica (modern Cádiz), possibly of Roman parents. After a career in the army (he was tribune in Syria in 35), he took up farming. His Res rustica in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the works of Cato the Elder and Varro, both of which he occasionally cites. A smaller book on trees, De arboribus, is usually attributed to him.