What about who defeated Greeks ? Mahameghavahan Aira Kharavela not only defeated Greek army thoroughly, he kicked their ass all the way from Mathura to Hindukush. Inscriptions at Hatigumpha shed some light on military might of Emperor Kharavela. Infantry was around 3 lakhs, Cavalry was to the tune of 1 lakh. Just imagine an Army of 4 lakh marching through during first century BCE.