The following year, in 226 BC, Aratus' army was defeated near Mount Lycaeum in Arcadia. The circumstances of the battle are unclear, but Achaean losses were heavy. Aratus was still able to turn this incident to his advantage, as it allowed him to march in secret to Mantinea and take that city. Importantly, this opened up the route from Argos to Megalopolis. From Mantinea, Aratus marched on to besiege Orchomenus. But Cleomenes marched for Megalopolis, capturing the fortress of Leuctra, 10 km from the city. Aratus came to the aid of the Megalopolitans, and was able to drive the Spartans back, but then failed to capitalise on his victory as the Spartans were able to fall back to a position of strength. Lydiades, furious, launched a cavalry attack on the newly organised Spartan troops, but Aratus did not follow and Lydiades was defeated and killed. The Spartans regained courage from this success, and attacked and routed the entire Achaean army.