As praetor and proconsul in 153–152, Mummius defeated the rebellious Lusitanians in southwestern Spain. In 152 he celebrated a triumph at Rome. As consul in 146, he was appointed commander of the war against the Achaean Confederacy. He defeated the Greek forces at Leucopetra on the Isthmus of Corinth and captured and destroyed Corinth. The Roman Senate then dissolved the Achaean Confederacy, and Mummius organized the province of Macedonia, which was to be supervised by Roman military commanders. Mummius’s indifference to works of art and ignorance of their value is shown by his well-known remark to those who contracted for the shipment of the treasures of Corinth to Rome, that “if they lost or damaged them, they would have to replace them with ware of equal value.” Mummius celebrated a second triumph. In 142 he was censor with Publius Cornelius Scipio Aemilianus; he helped alleviate Scipio’s severity.