The arrest accordingly took place in the most tumultuary fashion, so that the possession of Laconian names or Laconian shoes appeared sufficient ground for imprisonment: in fact they even entered the dwellings of the Roman envoys to seize the Lacedaemonians who had taken shelter there, and hard words were uttered against the Romans, although they did not lay hands on their persons. The envoys returned home in indignation, and made bitter and even exaggerated complaints in the senate; but the latter, with the same moderation which marked all its measures against the Greeks, confined itself at first to representations. In the mildest form, and hardly mentioning satisfaction for the insults which they had endured, Sextus Julius Caesar repeated the commands of the Romans at the diet in Aegium (spring of 607). But the leaders of affairs in Achaia with the new strategus Critolaus at their head strategus (from May 607 to May 608), as men versed in state affairs and familiar with political arts, merely drew from that fact the inference that the position of Rome with reference to Carthage and Viriathus could not but be very unfavourable, and continued at once to cheat and to affront the Romans. Caesar was requested to arrange a conference of deputies of the contending parties at Tegea for the settlement of the question. He did so; but, after Caesar and the Lacedaemonian envoys had waited there long in vain for the Achaeans, Critolaus at last appeared alone and informed them that the general assembly of the Achaeans was solely competent in this matter, and that it could only be settled at the diet or, in other words, in six months. Caesar thereupon returned to Rome; and the next national assembly of the Achaeans on the proposal of Critolaus formally declared war against Sparta.
Even now Metellus made an attempt amicably to settle the quarrel, and sent envoys to Corinth; but the noisy ecclesia, consisting mostly of the populace of that wealthy commercial and manufacturing city, drowned the voice of the Roman envoys and compelled them to leave the platform. The declaration of Critolaus, that they wished the Romans to be their friends but not their masters, was received with inexpressible delight; and, when the members of the diet wished to interpose, the mob protected the man after its own heart, and applauded the sarcasms as to the high treason of the rich and the need of a military dictatorship as well as the mysterious hints regarding an impending insurrection of countless peoples and kings against Rome. The spirit animating the movement is shown by the two resolutions, that all clubs should be permanent and all actions for debt should be suspended till the restoration of peace.
The Achaeans thus had war; and they had even actual allies, namely the Thebans and Boeotians and also the Chalcidians. At the beginning of 608 the Achaeans advanced into Thessaly to reduce to obedience Heraclea near to Oeta, which, in accordance with the decree of the senate, had detached itself from the Achaean league. The consul Lucius Mummius, whom the senate had resolved to send to Greece, had not yet arrived; accordingly Metellus undertook to protect Heraclea with the Macedonian legions. When the advance of the Romans was announced to the Achaeo-Theban army, there was no more talk of fighting; they deliberated only how they might best succeed in reaching once more the secure Peloponnesus; in all haste the army made off, and did not even attempt to hold the position at Thermopylae. But Metellus quickened the pursuit, and overtook and defeated the Greek army near Scarpheia in Locris. The loss in prisoners and dead was considerable; Critolaus was never heard of after the battle.
The remains of the defeated army wandered about Greece in single troops, and everywhere sought admission in vain; the division of Patrae was destroyed in Phocis, the Arcadian select corps at Chaeronea; all northern Greece was evacuated, and only a small portion of the Achaean army and of the citizens of Thebes, who fled in a body, reached the Peloponnesus. Metellus sought by the utmost moderation to induce the Greeks to abandon their senseless resistance, and gave orders, for example, that all the Thebans with a single exception, should be allowed their liberty; his well-meant endeavours were thwarted not by the energy of the people, but by the desperation of the leaders apprehensive for their own safety. Diaeus, who after the fall of Critolaus had resumed the chief command, summoned all men capable of bearing arms to the isthmus, and ordered 12,000 slaves, natives of Greece, to be enrolled in the army; the rich were applied to for advances, and the ranks of the friends of peace, so far as they did not purchase their lives by bribing the ruling agents in this reign of terror, were thinned by bloody prosecutions. The war accordingly was continued, and after the same style. The Achaean vanguard, which, 4000 strong, was stationed under Alcamenes at Megara, dispersed as soon as it saw the Roman standards. Metellus was just about to order an attack upon the main force on the isthmus, when the consul Lucius Mummius with a few attendants arrived at the Roman head-quarters and took the command. Meanwhile the Achaeans, emboldened by a successful attack on the too incautious Roman outposts, offered battle to the Roman army, which was about twice as strong, at Leucopetra on the isthmus. The Romans were not slow to accept it. At the very first the Achaean horsemen broke off en masse before the Roman cavalry of six times their strength; the hoplites withstood the enemy till a flank attack by the Roman select corps brought confusion also into their ranks. This terminated the resistance. Diaeus fled to his home, put his wife to death, and took poison himself. All the cities submitted without opposition; and even the impregnable Corinth, into which Mummius for three days hesitated to enter because he feared an ambush, was occupied by the Romans without a blow.
The renewed regulation of the affairs of Greece was entrusted to a commission of ten senators in concert with the consul Mummius, who left behind him on the whole a blessed memory in the conquered country. Doubtless it was, to say the least, a foolish thing in him to assume the name of "Achaicus" on account of his feats of war and victory, and to build in the fulness of his gratitude a temple to Hercules Victor; but, as he had not been reared in aristocratic luxury and aristocratic corruption but was a "new man" and comparatively without means, he showed himself an upright and indulgent administrator. The statement, that none of the Achaeans perished but Diaeus and none of the Boeotians but Pytheas, is a rhetorical exaggeration: in Chalcis especially sad outrages occurred; but yet on the whole moderation was observed in the infliction of penalties. Mummius rejected the proposal to throw down the statues of Philopoemen, the founder of the Achaean patriotic party; the fines imposed on the communities were destined not for the Roman exchequer, but for the injured Greek cities, and were mostly remitted afterwards; and the property of those traitors who had parents or children was not sold on public account, but handed over to their relatives. The works of art alone were carried away from Corinth, Thespiae, and other cities and were erected partly in the capital, partly in the country towns of Italy[22]: several pieces were also presented to the Isthmian, Delphic, and Olympic temples. In the definitive organization of the country also moderation was in general displayed. It is true that, as was implied in the very introduction of the provincial constitution[23], the special confederacies, and the Achaean in particular, were as such dissolved; the communities were isolated; and intercourse between them was hampered by the rule that no one might acquire landed property simultaneously in two communities.