After their overthrow by antimonarchical forces in Rome, the Tarquins fled to Clusium, a powerful Etruscan city ruled by the king Lars Porsena. There the Tarquins persuaded the king to help reinstate the monarchical form of government at Rome. Porsena invaded Rome. He took the Janiculan Hill and intended to cross the Tiber and occupy the city. Horatius Cocles, on guard at the Sublician Bridge at the time, along with Sp Lartius and T. Herminius, held up the Etruscans, while Roman soldiers dismantled the bridge behind them. This act of bravery saved the city from occupation and probably the Republican form of government as well.