Why Indo-Greeks entered India during Post Mauryan Period ?

Post Mauryan India - Connection between the Foreign Invasion of India - Great Wall of China & Gold Coins. How Indo-Greeks entered India during Post Mauryan Period. This is an important topic - Ancient history for UPSC.
For Polity Course - Download Bookstawa App [ ANDROID ]
play.google.co...
For Polity Course - Apple Devices
If you want to take this course on Apple store then you need to search 'MyInstitute' App. Download this App and enter org code - 'YLNOP' . And thats it .. you can take any Bookstawa Course.
Ancient History Playlist:
• Ancient History for UP...
Modern History Playlist:
• Modern History for UPS...