55 – 60 (Accusations of Octavian and Antonius against each other; Preparations for war)
61 – 68 (War of Actium)
69 – 77 (Antonius in Egypt; Negotiations; Battle; Death of Antonius)
78 – 87 (Cleopatra; Octavian in Alexandria; Antonius’ descendants)
2.56 – 89 (Triumviral narrative)
Suetonius, Life of Augustus
9 – 17 (Triumviral narrative)
26 – 27 (First consulship of Octavian, Triumvir)
Additional Sources The list is not exhaustive: choose the sources that are most relevant to your approach to the question, and supplement these with other sources you have found through your wider reading.
Cicero, Philippics, 10.7-15, 23-26; 11.26-40.
Selection of Cicero’s letters, see especially those written by Brutus, Cassius or their allies themselves (in bold):1
Aureus of 43 BC: RRC 490/2 = LACTOR H2. Aureus of 28 BC: BM CM 1995.4-1.1 = LACTOR H18. Aureus of 27 BC: RIC Augustus 277 = LACTOR H21.
Pliny NH 2.94 = LACTOR H3.
Livy Periochae (Summaries) 133 = LACTOR D2
Res Gestae – very carefully!
1 The first set of numbers is those of the traditional (vulgate) edition, the second set of numbers with SB in brackets is Shackleton-Bailey’s numbering system, which is the order used in the most recent Loeb edition.