The Lex Papia et Poppaea, also referred to as the Lex Iulia et Papia, was a Roman law introduced in 9 AD to encourage and strengthen marriage. It included provisions against adultery and against celibacy after a certain age and complemented and supplemented Augustus' Lex Iulia de maritandis ordinibus of 18 BC and the Lex Iulia de adulteriis coercendis of 17 BC. The law was introduced by the suffect consuls of that year, Marcus Papius Mutilus and Quintus Poppaeus Secundus, although they themselves were unmarried.