After 401, the Messenians disappeared again from mainland Greece for three decades. They reappeared as a consequence of that enormously momentous event, the defeat of the Spartans at Leuktra in 371 bc. In the fall of 370/69, Epaminondas led a huge expeditionary corps formed by the army of the Boeotian League and its allies, and the armies of Argos, Elis and Arcadia, in the first invasion of Laconia since the return of the Heraclids. Although vastly outnumbering the Spartans, the army was unable to take Sparta itself, and after ravaging the countryside between Sparta and the sea Epaminondas led his troops north along the Eurotas Valley and then marched out of Laconia into Messenia. The most direct way from Sparta to the Pamisos Valley led, then as now, across the Taygetos by way of the Langadha Pass. However, given the size of the army and the time of the year, it is likely that Epaminondas retraced his way back towards the Alpheios basin and marched into Messenia by way of its natural entrance, the Derveni Pass. The sources do not mention any resistance met by Epaminondas, and it is hardly thinkable that there could have been any. The allied army must have reached Mount Ithome undisturbed.