Cassius Dio, Roman History 59.25
“Once he arrived at the ocean—as if he were about to mount a campaign against Britain—[Gaius Caligula Caesar] stationed all his soldiers on the shore and climbed on a trireme. After sailing a little from the land, he sailed back again. Then, after that, he perched on a high platform and gave the soldiers a sign for battle, even urging the trumpeters to help them. Then, suddenly, he ordered them to collect seashells.
Once he acquired all of this booty—for he obviously needed spoils for his triumphal procession—he was deeply impressed with himself, as if he had made a slave of the ocean itself. Then he gave many gifts to his soldiers. He took the seashells back to Rome so he could display his war booty to them too.
The senate had no plan for how it could take these things calmly—because it understood that he was acting as if this were a big deal, nor could it praise him in any way. For if someone showers lavish praise or weighty honors for some middling or minor accomplishment, there is a lingering suspicion of hissing or mockery for it.
And yet, once he entered the city, Caligula nearly asked for the whole senate to be killed because it did not vote him immortal honors for this…”
ἐς δὲ τὸν ὠκεανὸν ἐλθὼν ὡς καὶ ἐν τῇ Βρεττανίᾳ στρατεύσων, καὶ πάντας τοὺς στρατιώτας ἐν τῇ ᾐόνι παρατάξας, τριήρους τε ἐπέβη καὶ ὀλίγον ἀπὸ τῆς γῆς ἀπάρας ἀνέπλευσε, καὶ μετὰ τοῦτο ἐπὶ βήματος ὑψηλοῦ ἱζήσας καὶ σύνθημα τοῖς στρατιώταις ὡς ἐς μάχην δούς, τοῖς τε σαλπικταῖς ἐξοτρύνας αὐτούς, εἶτ’ ἐξαίφνης ἐκέλευσέ σφισι τὰ κογχύλια συλλέξασθαι. λαβών τε τὰ σκῦλα ταῦτα (καὶ γὰρ λαφύρων δῆλον ὅτι πρὸς τὴν τῶν ἐπινικίων πομπὴν ἐδεῖτο) μέγα τε ἐφρόνησεν ὡς καὶ τὸν ὠκεανὸν αὐτὸν δεδουλωμένος, καὶ τοῖς στρατιώταις πολλὰ ἐδωρήσατο. καὶ ὁ μὲν ἐς τὴν ῾Ρώμην τὰ κογχύλια ἀνεκόμισεν, ἵνα καὶ ἐκεί-νοις τὰ λάφυρα δείξῃ· ἡ δὲ βουλὴ οὔθ’ ὅπως ἐπὶ τούτοις ἡσυχάζοι εἶχεν, ὅτι μεγαλοφρονούμενον αὐτὸν ἐπυνθάνετο, οὔθ’ ὅπως αὐτὸν ἐπαινέσειεν· ἂν γάρ τις ἐπὶ μηδεμιᾷ ἢ μικρᾷ τινι ἀνδραγαθίᾳ ἤτοι ἐπαίνους μεγάλους ἢ καὶ τιμὰς ἐξαισίους ποιῆται, διαμωκᾶσθαί τε καὶ διασιλλοῦν αὐτὴν ὑποπτεύεται. ὅμως ἐσελθὼν ἐς τὴν πόλιν τὴν μὲν βουλὴν ὀλίγου ἐδέησεν ἀπολέσαι πᾶσαν, ὅτι μὴ τὰ ὑπὲρ ἄνθρωπον αὐτῷ ἐψηφίσατο…
Suetonius, Gaius Caligula 46
“At last, as if he was about to finish the war, he had the battle line stretched out along the shore along with the ballistas and siege engines. When no one understood or had any idea what he was going to do, he suddenly ordered them to gather shells and fill their helmets and clothes, announcing that there were “the Ocean’s spoils, owed to the Capitoline and Palatine.”
He also had erected as a monument to his victory a really tall tower from which fires were meant to shine for the purpose of guiding the course of ships at night just like the lighthouse of Pharos. Once he promised to each soldier a bonus of one hundred denarii—as if this were a sign of extreme generosity—he said “Go happily away; leave here rich.”
Postremo quasi perpetraturus bellum, derecta acie in litore Oceani ac ballistis machinisque dispositis, nemine gnaro aut opinante quidnam coepturus esset, repente ut conchas legerent galeasque et sinus replerent imperavit, “spolia Oceani” vocans “Capitolio Palatioque debita,” et in indicium victoriae altissimam turrem excitavit, ex qua ut Pharo noctibus ad regendos navium cursus ignes emicarent; pronuntiatoque militi donativo centenis viritim denariis, quasi omne exemplum liberalitatis supergressus: “Abite,” inquit, “laeti, abite locupletes.”