Marital alliance happened between Selecus' hot daughter and Chandragupt after the latter slapped his to-be Sasurji in the one war where the Maurya empire expanded over what is now Afghanistan.
Chandragupt got his hot daughter and his territory.

Selecus got 400 elephants or some shit, big deal.
There was one nibba called Megasthenes who toured most of Bharat, he couldn't believe there was another civilization that was equal-equal to or even exceeding the Greek one, so he huffed on some copium that one of their wine-premi gods came here and taught Indians civilization, also believed one of the gods here was Hercules .
TLDR is these tribes were racist af and so we were back in the day, but both were ancient civilizations equal-equal to us.
What we have now is Gora doing WE WUZ KANGZ with his construct of "Western Civilization" and inferiority complex pajeet Elites after being under foreign heel for 1k years believe as gospel truth.