In early 458 or so the Phocians decided to campaign against the city of Doris. This province in central Greece was the original homeland of the Lacedaemonians. This gave Sparta an excuse to operate in the area. Although the sentiment to protect the motherland was a factor, it is obvious that Sparta had more practical motives. Boeotian lands were a prime target in this time.
The Lacedaemonians under Nicomedes, son of Cleombrotus, commanding for King Pleistoanax, son of Pausanias, who was still a minor, came to the aid of the Dorians with fifteen hundred Lacedaemonian hoplites, and ten thousand of their allies. After compelling the Phocians to restore the town on conditions, they began their retreat. The route by sea, across the Crissaean Gulf, exposed them to the risk of being stopped by the Athenian fleet; that across Geraneia seemed scarcely safe, the Athenians holding Megara and Pegae. So they resolved to remain in Boeotia, and to consider which would be the safest line of march. They had also another reason for this resolve. Secret encouragement had been given them by a party in Athens, who hoped to put an end to the reign of democracy and the building of the Long Walls. Meanwhile the Athenians marched against them with their whole levy and a thousand Argives and the respective contingents of the rest of their allies. Altogether they were fourteen thousand strong. The march was prompted by the notion that the Lacedaemonians were at a loss how to effect their passage, and also by suspicions of an attempt to overthrow the democracy.
This battle was quite large for the time. After a bloody fight, and some Athenian allies (Thessalian cavalry) switching sides, the Spartans and their allies were victorious. After entering the Megarid and cutting down the fruit trees, the Lacedaemonians returned home across Geraneia and the isthmus.
An embarrassed Athens, 62 days later, marched out and smashed the Boeotians at the battle of Oenophyta. The Athenians now were in a position to secure their north for 10 years. Also later this year, after a siege that started 459/458, Aegina surrendered to Athens. Later in the year the Athenians completed the two long walls that enclosed their harbours. They will build a second to Piraeus later. Athens made a treaty with the western Sicilian city of Segesta this year. Also the Athenians sent the home fleet, from Aegina, around the Peloponnese under the command of Tolmides. The fleet captured the Corinthian town of Chalcis and the rich city of Sicyon was defeated in battle. It seems that the early battle of Tanagra had to be avenged.