In B.C. 50, Sallust was legatus pro quaestore to Bibulus in Syria, according to Mommsen (Hermes, i. 171), who thinks that the Sallust to whom Cicero writes ad Fam. ii. 17 is the historian. In the same year he was expelled from the Senate by the censors, Appius Claudius and L. Piso.
Pseud.-Cic. in Sall. 16, ‘neque post illum delectum senatus vidimus te.’
In B.C. 49, Caesar reappointed him quaestor, and he resumed his place in the Senate.
Pseud.-Cic. in Sall. 17, ‘in senatum post quaesturam est reductus.’
In B.C. 48, he commanded a legion in Illyria without distinction (Orosius vi, 15, 8), and next year he was Caesar’s agent with the insurgent legions in Campania (Appian, B.C. ii. 92). In B.C. 46 he was praetor, and as such commanded successfully an expedition to seize the enemy’s stores in Cercina.
Bell. Afr. 8, ‘Item C. Sallustium Crispum praetorem ad Cercinam insulam versus, quam adversarii tenebant, cum parte navium ire iubet.’ (See also c. 34.)
At the end of the year he was appointed proconsul of Numidia.
Ibid. 97, ‘Ibi Sallustio pro consule cum imperio relicto ipse Zama egressus Uticam se recepit.’
As proconsul, he plundered the province, and bought, probably with the spoils, the horti Sallustiani, which afterwards belonged to the Roman emperors (see Tac. Ann. xiii. 47; Hist. iii. 82).
Pseud.-Cic. in Sall. 19, ‘Nonne ita provinciam vastavit, ut nihil neque passi sint neque exspectaverint gravius in bello socii nostri, quam experti sint in pace hoc Africam interiorem obtinente?’