History of the Peloponnesian War
Thucydides
Thucydides. History of the Peloponnesian War. Crawley, Richard, translator. London and Toronto: J. M. Dent and Sons Ltd.; New York: E. P. Dutton and Co., 1914.
the Chalcidian heavy infantry, and some auxiliaries with them, were beaten and retreated into Spartolus; but the Chalcidian horse and light troops defeated the horse and light troops of the Athenians.
The Chalcidians had already a few targeteers from Crusis, and presently after the battle were joined by some others from Olynthus;
upon seeing whom the light troops from Spartolus, emboldened by this accession and by their previous success, with the help of the Chalcidian horse and the reinforcement just arrived again attacked the Athenians, who retired upon the two divisions which they had left with their baggage.
Whenever the Athenians advanced, their adversary gave way, pressing them with missiles the instant they began to retire. The Chalcidian horse also, riding up and charging them just as they pleased, at last caused a panic amongst them and routed and pursued them to a great distance.