Amphipolis belonged to the Athenians, who had sent Thucydides and Eucles to guard the city lest it should be attacked by the Spartans. Thucydides had not only the city but a large district also to protect, and he was at this time stationed with his troops at some distance from Amphipolis, while Eucles was in the city itself.
The bridge over the Strymon, which led to the city, was carelessly guarded. So when, on a cold and wintry day, Brasidas reached the river, he took the bridge without difficulty, making prisoners the few soldiers who held it.
Messengers were at once sent to Thucydides to tell him that the Spartans had seized the bridge, and to beg him to come as quickly as possible to protect the city. Before the day was over, Thucydides had reached Eion, at the mouth of the Strymon. But his speed was of no avail, for Amphipolis had already surrendered, tempted by the easy terms that Brasidas had offered.
When the Athenians heard that the city was lost, they were indignant with Thucydides, and chiefly through the influence of Cleon, who disliked him, he was sent into exile.
The punishment was severe, but Thucydides was not idle during his banishment. He traveled from place to place, and everywhere he went he paid great attention to the ways of the people and to the manner in which their cities were governed. He himself wrote, "Associating with both sides, with the Peloponnesians quite as much as with the Athenians, because of my exile, I was thus enabled to watch quietly the course of events."
After having studied the "course of events," Thucydides began to write about the Peloponnesian war, and he became the greatest of all the historians of Greece.
After the surrender of Amphipolis in 424 b.c. , city after city forsook its allegiance to Athens. Scione did not even wait for the Spartans to demand admission, they opened their gates and begged Brasidas to enter. His presence pleased the people well, and when he had spoken to them their enthusiasm knew no bounds. They sent for a crown of gold and placed it on his head, calling him the "liberator of Hellas." Many of the people, too, cast garlands, over him as they were used to do to victors at a race.
Until now Brasidas had fought loyally for the sake of his country, but after the crown of gold had rested on his head he grew more ambitious to win fame for himself than glory for his country. It was his ambition that made him now do all that he could to keep Sparta from making peace with Athens, as she wished to do.
Cleon, too, was eager that the war should continue, not in order to win renown for himself, but rather that Athens might regain the empire that Brasidas was snatching from her grasp.
Two years after the surrender of Amphipolis, Cleon urged the Athenians to make an effort to retake the city. His rough eloquence persuaded them to undertake the task. He was himself appointed general, and was sent to Thrace at the head of a large army.
As he marched through the country he took several towns before he reached Eion, at the mouth of the river Strymon.
Here he halted, meaning to wait for reinforcements. But his soldiers had little respect for their general. Was he not after all only a leather-merchant? What could he know about war? And they clamoured to be led at once against the enemy. Cleon did not dare to refuse to do as his army wished, and he ordered his whole force to march toward Amphipolis to find out the strength of the enemy.
Brasidas was encamped with his army on the top of a hill, near to the city, from which he could watch every movement of the enemy.
When he saw the Athenians approaching, he ordered his men to march into the town where the Spartan Clearidas was now governor.
Cleon at once supposed that Brasidas had taken shelter within the walls of Amphipolis so as to avoid a battle. Feeling no longer anxious, he left his army near the city, but not drawn up ready for battle, and himself rode carelessly forward to look at the surrounding country.
Meanwhile some Athenian soldiers heard the restless movement of men and horses within the walls, others looking under the gates saw many feet gathering together. It was clear that preparations were being made by the Spartans to sally out and attack them.
A messenger was sent in haste to find Cleon. The general no sooner heard the report than he hurried back to his army, and commanded it at once to retreat toward Eion. To do this the Athenians had to march past Amphipolis with their right sides unprotected, for their shields were carried always on their left arm, which was now the farthest from the walls of the city.
The men had no confidence in their general, and they began to retreat in disorder. From within the city, Brasidas was watching with keen eyes the movements of the enemy. Suddenly he cried, "These men will never withstand our onset. Look at their quivering spears and nodding heads. Men who are going to fight never march in such a fashion as this. Open the gates at once that I may rush on them forthwith."
So the gates of the city were flung open and out dashed Brasidas followed by his men, as he charged right into the centre of the Athenian army. The left wing, seized with panic, fled. Clearidas meanwhile led a body of men against the right wing, and a fierce struggle followed.
Cleon, less at home on a battlefield than in the assembly at Athens, grew frightened at the unusual sights and sounds, and fled, leaving his army without a leader. As he fled an arrow pierced him and he fell to the ground, wounded to death.
Brasidas also, as he turned to go to the help of Clearidas, was wounded. His followers carried him within the walls of the city. He lived long enough to know that the Athenians were utterly defeated.
The people of Amphipolis had learned to love Brasidas, and he was buried with great splendour in the market-place. A temple was built to his honour, and every year sacrifices were offered and games were held in memory of the brave soldier.
So deep was the affection of the people that they determined to forget that their city had been founded by an Athenian, and henceforth to count Brasidas the Spartan the true founder of Amphipolis.
As Cleon and Brasidas were both dead, the peace party, with Nicias at its head, was able to arrange terms with the king of Sparta, and in spring, 421 b.c. , the Peace of Nicias was signed. The first part of the Peloponnesian War, which had begun ten years before, was ended.