History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
But the Boeotians did not any the more give up the ten days' truce, although the Corinthians demanded it and accused them of having agreed with themselves to do so. Between the Corinthians, however, and the Athenians there was a cessation of activities without an actual truce.
The same summer the Lacedaemonians, under the command of Pleistoanax, son of Pausanias, king of the Lacedaemonians, made an expedition with all their forces into the territory of the Parrhasians of Arcadia, who were subjects of the Mantineans. They had been called in by the Parrhasians on account of a factional quarrel, and intended also to demolish, if possible, the fort at Cypsela, which, being situated in Parrhasian territory, the Mantineans had constructed and themselves garrisoned for the annoyance of the district Sciritis[*](The mountainous region between the upper Eurotas and the valley of the Oenus, one of the most important districts of the Perioeci.) in Laconia.