Agis and Cleomenes (Cleomenes.3.5-Cleomenes.4.1)

since he was of the opinion that in this way alone would they be safe from the attacks of their enemies without. Nearly all the other Peloponnesians adopted his views, but the Lacedaemonians, the Eleians, and the Arcadians who sided with the Lacedaemonians held aloof. Therefore, as soon as Leonidas was dead, Aratus began to harass the Arcadians, and ravaged the territories of those especially who were adjacent to Achaea. His object was to put the Lacedaemonians to the test, and he despised Cleomenes as a young and inexperienced man.

Upon this, the ephors began operations by sending Cleomenes to occupy the precinct of Athena at Belbina. This commands an entrance into Laconia, and was at that time a subject of litigation with the Megalopolitans. After Cleomenes had occupied and fortified this place, Aratus made no public protest, but led out his forces one night and tried to surprise Tegea and Orchomenus.