As empress, Domna was famous for her political, social, and philosophical influence. She received titles such as "Mother of the Invincible Camps". After the elder of her sons, Caracalla, started ruling with his father, she was briefly co-empress with Caracalla's wife, Fulvia Plautilla, until the latter fell into disgrace. Following the death of Severus in 211, Domna became the first empress dowager to receive the title combination ""Pia Felix Augusta"", which may have implied greater powers being vested in her than what was usual for a Roman empress mother. Her sons succeeded to the throne. They had a conflictual relationship and Domna acted as their mediator, but Caracalla had his brother Geta assassinated later that year.