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.

The forces of the Athenians were strengthened by some Thessalian cavalry, who came in accordance with the terms of the alliance, but they deserted to the Lacedaemonians in the course of the action.

The battle took place[*](456 B.C.) at Tanagra in Boeotia, and in it the Lacedaemonians and their allies were victorious, and there was much slaughter on both sides.