[prox]

Speaking to some people from India, and my own readings what combined their society was a couple of things : a deep connection to the traditions such as the vedas, sanskrit, gods, brahmanism. And even if there was divergence, it was usually with a deep respect for what had gone before. So surely while there was a lot of cultural divergence, there was also a lot of things that made it into the India we see today. Some empires also endured a long time to make more of cultural unity. I am not sure in how far Bharat was used for the whole subcontinent and where.

[kumarvvr]

True. There were a multitude of kings, queens and kingdoms across India, but the study and spread of the cultural and literary roots of India happened all across the sub-continent.

That is why, even today, the same chants used in temples in the north, are used in the south. The text, meanings, rituals, practices, etc, may have taken a regional flavor, but the essence is the same, the core is the same and the philosophical idea behind it is the same.

[hef19898]

Map covering the different languages spoken in modern India:

https://www.mapsofindia.com/maps/india/indianlanguages.htm