As may be imagined, a man of such indomitable courage could not fail to make his mark. Antigonus wished to engage him in his service, but Philopœmen refused, as he knew his temper would not let him serve under others. His thirst for war took him to Crete, where he brought the cavalry of that island to a state of perfection never before known in Greece.
And now a new step in political progress took place in the Peloponnesus. The cities of Achæa joined into a league for common aid and defence. Other cities joined them, until it was hoped that all Peloponnesus would be induced to combine into one commonwealth. There had been leagues before in Greece, but they had all been dominated by some one powerful city. The Achæan League was the first that was truly a federal republic in organization, each city being an equal member of the confederacy.
Philopœmen, whose name had grown to stand highest among the soldiers of Greece, was chosen as general of the cavalry, and at once set himself to reform its discipline and improve its tactics. By his example he roused a strong warlike fervor among the people, inducing them to give up all display and exercise but those needed in war. "Nothing then was to be seen in the shops but plate breaking up or melting down, gilding of breastplates, and studding buckles and bits with silver; nothing in the places of exercise but horses managing and young men exercising their arms; nothing in the hands of the women but helmets and crests of feathers to be dyed, and the military cloaks and riding frocks to be embroidered.... Their arms becoming light and easy to them with constant use, they longed for nothing more than to try them with an enemy, and fight in earnest."
Two years afterwards, in 208 B.C., Philopœmen was elected strategus, or general in-chief, of the Achæan league. The martial ardor of the army he had organized was not long left unsatisfied. It was with his old enemy, the Spartans, that he was first concerned. Machanidas, the Spartan king, having attacked the city of Mantinea, Philopœmen marched against him, and soon gave him other work to do. A part of the Achæan army flying, Machanidas hotly pursued. Philopœmen held back his main body until the enemy had become scattered in pursuit, when he charged upon them with such energy that they were repulsed, and over four thousand were killed. Machanidas returning in haste, strove to cross a deep ditch between him and his foe; but as he was struggling up its side, Philopœmen transfixed him with his javelin, and hurled him back dead into the muddy ditch.
This victory greatly enhanced the fame of the Arcadian general. Some time afterwards he and a party of his young soldiers entered the theatre during the Nemean games, just as the actor was speaking the opening words of the play called "The Persians:"
"Under his conduct Greece was glorious and was free."
The whole audience at once turned towards Philopœmen, and clapped their hands with delight. It seemed to them that in this valiant warrior the ancient glory of Greece had returned, and for the time some of the old-time spirit came back. But, despite this momentary glow, the sun of Grecian freedom and glory was near its setting. A more dangerous enemy than Macedonia had arisen. Rome, which Pyrrhus had gone to Italy to seek, had its armies now in Greece itself, and the independence of that country would soon be no more.
The next exploit of Philopœmen had to do with Messenia. Nabis, the new Spartan king, had taken that city at a time when Philopœmen was out of command, the generalship of the League not being permanent. He tried to persuade Lysippus, then general of the Achæans, to go to the relief of Messenia, but he refused, saying that it was lost beyond hope. Thereupon Philopœmen set out himself, followed by such of his fellow citizens as deemed him their general by nature's commission. The very wind of his coming won the town. Nabis, hearing that Philopœmen was near at hand, slipped hastily out of the city by the opposite gates, glad to get away in safety. He escaped, but Messenia was recovered. The martial spirit of Philopœmen next took him to Crete, where fighting was to be had to his taste. Yet he left his native city of Megalopolis so pressed by the enemy that its people were forced to sow grain in their very streets. However, he came back at length, met Nabis in the field, rescued the army from a dangerous situation, and put the enemy to flight. Soon after he made peace with Sparta, and achieved a remarkable triumph in inducing that great and famous city to join the Achæan League. In truth, the nobles of Sparta, glad to have so important an ally, sent Philopœmen a valuable present. But such was his reputation for honor that for a time no man could be found who dared offer it to him; and when at length the offer was made he went to Sparta himself, and advised its nobles, if they wanted any one to bribe, to let it not be good men, but those ill citizens whose seditious voices needed to be silenced.
In the end Sparta was destined to suffer at the hands of its incorruptible ally, it having revolted from the League. Philopœmen marched into Laconia, led his army unopposed to Sparta, and took possession of that famous seat of Mars, within which no hostile foot had hitherto been set. He razed its walls to the ground, put to death those who had stirred the city to rebellion, and took away a great part of its territory, which he gave to Megalopolis. Those who had been made citizens of Sparta by tyrants he drove from the country, and three thousand who refused to go he sold into slavery; and, as a further insult, with the money received from their sale he built a colonnade at Megalopolis.
Finally, as a death-blow to Spartan power, he abolished the time-honored laws of Lycurgus, under which that city had for centuries been so great, and forced the people to educate their children and live in the same manner as the Achæans. Thus ended the glory of Sparta. Some time afterwards its citizens resumed their old laws and customs, but the city had sunk from its high estate, and from that time forward vanished from history.