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.
About the same time the Lacedaemonians marched out with all their people to Leuctra upon their frontier, opposite to Mount Lycaeum, under the command of Agis, son of Archidamus, without any one knowing their destination, not even the cities that sent the contingents.