u/CompoteMelodic981

This question seem to baffle many Hindu nationalists, who have come up with many hypotheses.

The simplest answers are also sometimes the most accurate.

The video here talks about caste system and slavery in Kerala during 1500-1900s. How dalits etc lived as slaves, how the kings, slavers(British, malayali Muslim, hindu upper caste etc) benefitted. And also narrates stories where people converted to other religions.