This passage probably refers to the tumultuous scene on the night between 24th and 25th Jan., A.D. 41, before Claudius' accession, after the murder of Caligula (cf. the pun in _caliganti_), when rival claimants to the throne were put forward, and the Senate wished to restore the republic (cf. _discordia membra trepidarent_). Sen. _ad Polyb._ 13, 1, uses similar language of Claudius, 'Sidus hoc, quod praecipitato in profundum et demerso in tenebras orbi refulsit, semper luceat.'
As Curtius says nothing but good about the reign of Claudius, he probably wrote shortly after his accession. The passage in iv. 4, 21 (above) also fits in with this view, as there was little fighting in the Roman world from 17 to 43 A.D. His bold tone with regard to rulers would also suit this time, while it would have been dangerous under Caligula, or from 43 to 54 A.D.
Cf. viii. 5, 6, 'Non deerat talia concupiscenti perniciosa adulatio, perpetuum malum regum, quorum opes saepius adsentatio quam hostis evertit.'
This tone also renders it impossible to identify him with Curtius Rufus, mentioned in Tac. _Ann._ xi. 21, as governor of Africa, and as 'adversus superiores tristi adulatione, adrogans minoribus, inter pares difficilis.'
Seneca is supposed to have quoted his contemporary Curtius once or twice. Cf. Sen. _Ep._ 56, 9, 'Nihil tam certum est quam otii vitia negotio discuti'; and Curt. vii. 1, 4, 'Satis prudens, otii vitia negotio discuti.' Cf. also viii. 10, 29 with Sen. _Ep._ 59, 12.
Curtius claims to transcribe his authorities carefully. Cf. ix. 1, 34, 'Equidem plura transscribo quam credo: nam nec adfirmare sustineo, de quibus dubito, nec subducere quae accepi.'
Curtius' statements are usually parallel to those of one or other of the historians of Alexander, but he appeals only twice to other authorities by name.
ix. 8, 15, 'Clitarchus (c. 300 B.C.) est auctor.'
ix. 5, 21, 'Ptolemaeum (c. 300 B.C.), qui postea regnavit, huic pugnae adfuisse auctor est Clitarchus et Timagenes (c. 55 B.C.). Sed ipse ... afuisse se missum in expeditionem memoriae tradidit.'
The rhetorical tone of the work is seen in the speeches and letters. For the latter cf. iv. 1, 10-74. Curtius has little technical knowledge of war or politics. Thus Alexander's assumption of oriental pomp to conciliate the Asiatics is looked on as ὕβρις. Cf. iii. 12, 18. Like Livy, he attempts to depreciate Alexander's abilities by unduly accentuating his good fortune.