This article aims to give a survey of preparations conducted by Spartan king Agis III before he commenced his war against Macedonians. Based on the remaining narrative sources, mostly Arrian, Diodorus, Curtius Rufus and Justin, the author gives an account of king Agis’ doings up until the very beginning of his war. The author argues also why is that a real, full open war, not a "rebellion" as it is dubbed in some of the literature. Author gives his opinion about (...) the beginning of the preparations for the open war and concludes that they began in November 333 BC, at latest. This article also tackles the question of mercenaries which Agis took after the Battle of Issus. Due to the uncertainty of the sources themselves it can be concluded at best that Agis hired a great number of them after Issus. (shrink)