Thenceforth the defence of the northern and eastern frontiers of Macedonia or, in other words, of the frontier of Hellenic civilization against the barbarians devolved on the Romans. It was conducted by them with inadequate forces and not, on the whole, with befitting energy; but with a primary view to this military object the great Egnatian highway was constructed, which as early as the time of Polybius ran from Apollonia and Dyrrhachium, the two chief ports on the west coast, across the interior to Thessalonica, and was afterwards prolonged to the Hebrus (Maritza)[18]. The new province became the natural basis, on the one hand for the movements against the turbulent Dalmatians, and on the other hand for the numerous expeditions against the Illyrian, Celtic, and Thracian tribes settled to the north of the Grecian peninsula, which we shall afterwards have to exhibit in their historical connection.

Greece proper had greater occasion than Macedonia to congratulate herself on the favour of the ruling power; and the Philhellenes of Rome might well be of opinion that the calamitous effects of the war with Perseus were disappearing, and that the state of things in general was improving there. The bitterest abettors of the now dominant party, Lyciscus the Aetolian, Mnasippus the Boeotian, Chrematas the Acarnanian, the infamous Epirot Charops whom honourable Romans forbade even to enter their houses, descended one after another to the grave; another generation grew up, in which the old recollections and the old antagonisms had faded. The Roman senate thought that the time for general forgiveness and oblivion had come, and in 604 released the survivors of those Achaean patriots who had been confined for seventeen years in Italy, and whose liberation the Achaean diet had never ceased to demand. Nevertheless they were mistaken. How little the Romans with all their Philhellenism had been successful in heartily conciliating Hellenic patriotism, was nowhere more clearly apparent than in the attitude of the Greeks towards the Attalids. King Eumenes II had been, as a friend of the Romans, extremely hated in Greece[19]; but scarcely had a coldness arisen between him and the Romans, when he became suddenly popular in Greece, and the Hellenic hopefuls expected the deliverer from a foreign yoke to come now from Pergamus as formerly from Macedonia. Social disorganization more especially was visibly on the increase among the petty states of Hellas now left to themselves. The country became desolate not through war and pestilence, but through the daily increasing disinclination of the higher classes to trouble themselves with wife and children; on the other hand the criminal or the thoughtless flocked as hitherto chiefly to Greece, there to await the recruiting officer.

The communities sank into daily deeper debt, and into financial dishonour and a corresponding want of credit: some cities, more especially Athens and Thebes, resorted in their financial distress to direct robbery, and plundered the neighbouring communities. The internal dissensions in the leagues also - e. g. between the voluntary and the compulsory members of the Achaean confederacy - were by no means composed. If the Romans, as seems to have been the case, believed what they wished and confided in the calm which for the moment prevailed, they were soon to learn that the younger generation in Hellas was in no respect better or wiser than the older. The Greeks directly sought an opportunity of picking a quarrel with the Romans.

In order to screen a foul transaction, Diaeus, the president of the Achaean league for the time being, about 605 threw out in the diet the assertion that the special privileges conceded by the Achaean league to the Lacedaemonians as members - viz. their exemption from the Achaean criminal jurisdiction, and the right to send separate embassies to Rome - were not at all guaranteed to them by the Romans.

It was an audacious falsehood; but the diet naturally believed what it wished, and, when the Achaeans showed themselves ready to make good their assertions with arms in hand, the weaker Spartans yielded for the time, or, to speak more correctly, those whose surrender was demanded by the Achaeans left the city to appear as complainants before the Roman senate. The senate answered as usual that it would send a commission to investigate the matter; but instead of reporting this reply the envoys stated in Achaia as well as in Sparta, and in both cases falsely, that the senate had decided in their favour. The Achaeans, who felt more than ever their equality with Rome as allies and their political importance on account of the aid which the league had just rendered in Thessaly against the pseudo-Philip, advanced in 606 under their strategus Damocritus into Laconia: in vain a Roman embassy on its way to Asia, at the suggestion of Metellus, admonished them to keep the peace and to await the commissioners of the senate. A battle took place, in which nearly 1000 Spartans fell, and Sparta might have been taken if Damocritus had not been equally incapable as an officer and as a statesman. He was superseded, and his successor Diaeus, the instigator of all this mischief, zealously continued the war, while at the same time he gave to the dreaded commandant of Macedonia assurances of the full loyalty of the Achaean league. Thereupon the long-expected Roman commission made its appearance, with Aurelius Orestes at its head; hostilities were now suspended, and the Achaean diet assembled at Corinth to receive its communications. They were of an unexpected and far from agreeable character. The Romans had resolved to cancel the unnatural and forced[20] inclusion of Sparta among the Achaean states, and generally to act with vigour against the Achaeans. Some years before (591) these had been obliged to release from their league the Aetolian town of Pleuron[21]; now they were directed to renounce all the acquisitions which they had made since the second Macedonian war - viz. Corinth, Orchomenus, Argos, Sparta in the Peloponnesus, and Heraclea near to Oeta - and to reduce their league to the condition in which it stood at the end of the Hannibalic war. When the Achaean deputies learned this, they rushed immediately to the market-place without even hearing the Romans to an end, and communicated the Roman demands to the multitude; whereupon the governing and the governed rabble with one voice resolved to arrest at once the whole Lacedaemonians present in Corinth, because Sparta forsooth had brought on them this misfortune.

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.