<P> Publius Horatius Cocles was an officer in the army of the ancient Roman Republic who famously defended the Pons Sublicius from the invading army of Lars Porsena, king of Clusium in the late 6th century BC, during the war between Rome and Clusium . </P> <P> In 509 BC, the army of Clusium marched on Rome and attacked the city . Concentrating his forces on the Etruscan side of the Tiber, Porsena assaulted the Janiculum and took it from the terrified Roman recruits with all its stores . An Etruscan garrison was detailed to hold it . Porsena's army made for the Pons Sublicius, but found there a Roman line of battle across the bend of the river . Porsena drew up a line of battle opposite it, apparently without hindrance, relying on numerical superiority to cow the Romans . The Tarquins commanded the Etruscan left wing facing the troops of Spurius Lartius and Titus Herminius . Octavius Mamilius took the Etruscan right commanding rebel Latins, facing Marcus Valerius Volusus and Titus Lucretius Tricipitinus . Porsena commanded the Etruscan center, facing the two consuls . </P>

Who defended a bridge when rome was under attack