Little is known of Aulus Plautius's early career. An inscription reveals he was involved in the suppression of a slave revolt in Apulia, probably in 24, alongside Marcus Aelius Celer. He was suffect consul for the second half of 29, and held a provincial governorship, probably of Pannonia, in the early years of Claudius's reign: another inscription shows he oversaw the building of a road between Trieste and Rijeka at this time.
Claudius appointed him to lead his invasion of Britannia in 43, in support of Verica, king of the Atrebates and an ally of Rome, who had been deposed by his eastern neighbours the Catuvellauni. The army was composed of four legions, IX Hispana, then in Pannonia, II Augusta, XIV Gemina, and XX Valeria Victrix, plus approximately 20,000 auxiliary troops, including Thracians and Batavians. In this occasion, II Augusta was commanded by the future emperor Vespasian. Three other men of appropriate rank to command legions are known to have been involved in the invasion: Vespasian's brother Titus Flavius Sabinus II and Gnaeus Hosidius Geta appear in Dio Cassius's account of the invasion; Gnaeus Sentius Saturninus is mentioned by Eutropius, although as a former consul he may have been too senior, and perhaps accompanied Claudius later.
On the beaches of northern Gaul Plautius faced a mutiny by his troops, who were reluctant to cross the Ocean and fight beyond the limits of the known world. They were persuaded after Claudius's freedman and secretary Narcissus addressed them: seeing a former slave in place of their commander, they cried "Io Saturnalia!" (Saturnalia being a Roman festival in which social roles were reversed for the day) and the mutiny was over.
The invasion force sailed in three divisions, and is generally believed to have landed at Richborough in Kent, although parts may have landed elsewhere (see Site of the Claudian invasion of Britain). The Britons, led by Togodumnus and Caratacus of the Catuvellauni, were reluctant to fight a pitched battle, relying on instead on guerrilla tactics. However, Plautius defeated first Caratacus, then Togodumnus, on the rivers Medway and Thames. Togodumnus died shortly afterwards, although Caratacus survived and continued to be a thorn in the invaders' side.
Having reached the Thames, Plautius halted and sent for Claudius, who arrived with elephants and heavy artillery and completed the march on the Catuvellaunian capital, Camulodunum (Colchester). A Roman province was established in the conquered territory, and alliances made with nations outside direct Roman control. Plautius became governor of the new province, until 47 when he was replaced by Publius Ostorius Scapula. On his return to Rome and civil life, Plautius was granted an Ovation, during which the emperor himself walked by his side to and from the Capitol.
Plautius was a (probably distant) relative of Claudius's first wife, Plautia Urgulanilla. Quintus Plautius, who was consul in 36, was probably his younger brother. His sister married Publius Petronius; their (adopted?) son, Publius Petronius Turpilianus, was later consul and governor of Britain.
Plautius's wife, Pomponia Graecina, after the execution of her kinswoman Julia Drusi Caesaris by Claudius and Messalina, remained in mourning for forty years in open, and unpunished, defiance of the emperor. In 57 she was charged with a "foreign superstition", interpreted by some to mean conversion to Christianity. According to Roman law, she was tried by her husband before her kinsmen, and was acquitted.
Plautius was probably the uncle whose "distinguished service" saved Plautius Lateranus from the death penalty in 48 after his affair with Messalina. By the time Lateranus was eventually executed, in 65 for his part in a conspiracy against Nero, his uncle was probably dead and could no longer help him.
Three other men of the same name are known: