Ancus Marcius was the legendary fourth king of Rome, who traditionally reigned 24 years. Upon the death of the previous king, Tullus Hostilius, the Roman Senate appointed an interrex, who in turn called a session of the assembly of the people who elected the new king. Ancus is said to have ruled by waging war as Romulus did, while also promoting peace and religion as Numa Pompilius did.