In 510 a conspiracy was formed against Tarquin by BRUTUS, COLLATINUS, and others, and the gates of the city were closed against him. (Footnote: The cause of the conspiracy was the violence offered by Sextus, Tarquin's son, to Lucretia, wife of Collatinus. Unable to bear the humiliation, she killed herself in the presence of her family, having first appealed to them to avenge her wrongs) A Republic was then formed, with two Consuls at the head of the government. Tarquin made three attempts to recover his power at Rome, all unsuccessful. (Footnote: The victory of Lake Regillus, which has been painted by Macaulay in glowing colors, was gained over Tarquin in 509.) In the last attempt (508), he was assisted by PORSENA, king of the Etruscans. They advanced against the city from the north. HORATIUS COCLES, a brave young man, alone defended the bridge (_pans sublicius_) over the Tiber until it was torn down behind him. He then swam the river in safety to his friends. (Footnote: See Macaulay's "Lays of Ancient Rome.") During the siege of the city, QUINTUS MUCIUS SCAEVOLA, a courageous youth, stole into the camp of the enemy with the intention of killing King Porsena, but by mistake killed his secretary instead. He was seized and carried to Porsena, who tried to frighten him by threats of burning. Instead of replying, Scaevola held his right hand on the burning altar until it was consumed. The king, admiring this heroic act, pardoned him. Out of gratitude, Scaevola told the king that three hundred other men as brave as himself had sworn to kill him. Porsena was so alarmed, that he made peace, and withdrew from the city. Mucius received his name Scaevola (left-handed) on account of this loss of his right hand. Tarquin went to Tusculum, where he spent the rest of his days in retirement. In 494 the plebeians at Rome rebelled, because they were exhausted by taxes and military service. A large part of them left the city, and crossed the Anio to a mountain (Mons Sacer) near by. The Senate sent MENENIUS AGRIPPA to treat with them. By his exertions (Footnote: Menenius is said to have related for them the famous fable of the belly and members.) the people were induced to return to the city, and for the first time were allowed to have officers chosen from their own ranks to represent their interests. These officers were called Tribuni Plebis.