ANCUS Marcius, the fourth king of the Romans, succeeded Tullus Hostilius about 638 B.C., and reigned until 614. He defeated the Latine and other tribes, enlarged Rome by joining to it the Janiculum, and made the harbour of Ostia. In his reign many of the conquered Latins were incorporated with the Roman state, and not receiving the full franchise, formed, according to Niebuhr, the first elements of the Roman plebs.