Tiberius' military career started in the Third Punic War, as military tribune appointed to the staff of his brother in law, Scipio Aemilianus. During his tenure as military tribune under Aemilianus, Tiberius became known for his bravery and discipline, recorded as the first to scale the enemy walls of Carthage during the Roman siege in 146 BC. In 137 BC he was appointed quaestor to consul Gaius Hostilius Mancinus and served his term in Numantia (Hispania province). The campaign was part of the Numantine War and was unsuccessful; Mancinus's army suffered major defeats and Mancinus himself had tried disgracefully to withdraw at night and caused his rearguard to be cut to pieces and the Roman camp looted.