Signa - late republic and reign of Augustus

[M. Caecilius]

Do any of you know literary sources from the top of your head about:

No, not of the top of my head. But I can check some sources. :mrgreen:

[*]The return of Crassus' standards by the Parthians

Non-exhaustive, of course:
-- Suetonius, Div. Aug. 21.3 (the Crassan standards together with the Antonian)
-- Augustus, Res Gestae 29 mentions the standards lost in Spain (during the Cantabrian campaign, probably), Gaul (unknown), Dalmatia (Gabinius and Vatinius) and Parthia (Crassus and Antony), the latter deposited in the temple of Mars Ultor)
-- Cassius Dio, 53.33.1. The Parthian standards and captives are returned in exchange for the son of Phraates

Also Horace, Odes 4.15.6-8, Ep. 1.12.27-8, 18.56-7; Propertius 4.6.79-84; Ovid, Fasti 5.580-94, 6.465-8, Tr. 2.227-8;

And modern sources
-- M. Wissemann, Die Parther in der Augusteischen Dichtung; J.P.A. van der Vin, 'The return of Roman ensigns from Parthia', Bulletin Antieke Beschaving 56 (1981), 117-39, this taken from references in J. W. Rich, Augustus's Parthian Honours, the Temple of Mars Ultor and the Arch in the Forum Romanum, Papers of the British School at Rome, Vol. 66 (1998), pp. 71-128, available on Jstor.

Any other significant event involving standards (not "just" about a battle, but with more importance)

Plutarch Crassus 23 mentions the bad omen of the standards sticking in the earth before his march against Parthia, something that happened also during other wars.

There are several instances where generals encourage their soldiers by throwing the standards into the enemy ranks; loss of a standard also causes Legio X to invade Britain despite their qualms.The aquilifer jumped off the ship, and the reluctant soldiers had to follow or lose their eagle (Caesar, BG.4.25).

Is that the kind of other information you are looking for?

[Titvs Statilivs Castvs]

@Byron: yes I looked, nothing about the standards though (as far as I've seen).

@Max: thank you! Some of them I already had, some of them I had not. It's indeed that kind of information I was looking for, but for now, I have enough.

Thank you very much for your help, everyone!