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 infantry occupied a hill on either side, with a plain between, while the cavalry of both armies at first galloped down into the plain and engaged in battle; then Brasidas and Perdiccas, after the Lyncestian hoplites had come forward from the hill in conjunction with their own cavalry and were ready to fight, advanced also in their turn and joined battle, routing the Lyncestians and destroying many, while the rest escaped to the high places and kept quiet.
After this they set up a trophy and halted for two or three days, awaiting the Illyrians, who had been hired by Perdiccas and were momentarily expected. Then Perdiccas wished, on their arrival, to go forward against the villages of Arrhabaeus instead of sitting idle; but Brasidas was solicitous about Mende, fearing that it might suffer some harm if the Athenians should sail there before his return; and, besides, the Illyrians had not appeared, so that he was not eager to go on, but rather to retreat.