He was the oldest son of Quintus Caecilius Metellus and grandson of Lucius Caecilius Metellus. A brilliant general, he fought in the Third Macedonian War and played a pivotal role in the Fourth. Under his leadership in 148 BC when still a Praetor the Roman troops twice defeated Andriscus, a self-proclaimed pretender to the Macedonian throne who claimed to be son of Perseus, last king of the Antigonid dynasty. Andriscus had risen against Rome intending to liberate Macedonia with an army recruited from Thrace. Under Metellus' authority Macedonia was reduced and made a Roman province. For that he won his agnomen and since then introduced the Clypeus Macedoniccus in his family's medals. In 146 BC, he defeated Critolaos of Megalopolis at the Battle of Scarpheia and the Arcadians at Chaeronea but Metellus was then sent to fight in the Achaean War to avenge an insult offered to a Roman Embassy at Corinth. He fought under the command of Consul Lucius Mummius Achaicus whose ultimate victory in the war against the Achaean League delayed Macedonicus from celebrating immediately the honours of the Triumph which his success at the battle of Scarpheia merited. On his return to Italy he received the honour of a Triumph and the title of Macedonicus. He then built at the Campus Martius a Porticus of Cecilius which later became the Porticus of Octavia. He also built two grandiose temples: one dedicated to Jupiter and the other to Juno. These were the first marbletemples in Rome, ornamented with equestrian statues of the various Generals of Alexander brought by him from Greece. In 143-142 BC, when Consul, he campaigned against the Celtiberians in central Hispania during the Numantine War, defeating the Arevaci, Lusones, Belli, Titii and the Vaccaei. He did not confront the city ofNumantia, which then became the focus of the war and which resisted for ten years. In 133 BC, he gave a speech attacking Tiberius Gracchus regarding that tribune's plan to bypass the traditional prerogative of the senate and keep the vast fortune of the recently deceased Attalus III of Pergamon under the control of the Plebeian Assembly. Attalus had bequeathed his kingdom to the people of Rome. Metellus was elected Censor in 131 BC, boldly pledging to halt the growing degradation of Roman custom. In a speech which he delivered at his appointment, he proposed that matrimony was to be mandatory for all citizens, in order to put an end to the libertine behaviour then already widespread. A century later Augustus caused this speech to be read at the Senate and published as an Edict for the knowledge and regeneration of the Roman People. His moralizing efforts awakened strong popular opposition, led by the Tribune Gaius Atinius Labeo Macerio whom he had previously expelled from the Senate. He was almost killed by the mob on the Tarpeian Rock. Later there were some disagreements between him and Scipio Aemilianus, but he never lost sight of the merit of this adversary, whose death he mourned, ordering his sons to transport Aemilianus' body to the crematory pyre. Celebrated for his eloquence and his taste for the Arts, he died in 116 BC/115 BC. He was generally respected as the paradigm of the fortunate Roman for from an illustrious birth he united all manner of civil and military honours, and left a large family of four sons, of whom one was then Consul, two had already been and one would be soon. His two sons-in-law, Publius Cornelius Scipio Nasica Serapio and Gaius Servilius Vatia would also attain the consulship.
Metellus was played by Gordon Mitchell in the 1961 film The Centurion. "Metellus raising the siege", a painting by Armand-Charles Caraffe, commemorates the legend of Metellus lifting the siege of Centobrigia in 142 BC, in order to spare the lives of innocents.
