Indian Civilization is the world’s longest surviving civilization from over last 5000 years. India or Bharat was always one country comprising of numerous kingdoms akin to today's India with a number of states. Though we have different states today it doesn't mean we are different countries today.
It is cultures which make a country not states or kingdoms. For eg: you cannot take half of France and half of Germany to create a country. The French follow the French culture and the Germans follow German culture and that is why they are nations. Even if you divide Germany into two parts (this was done) they would face absolutely no problem in joining back together.
Culturally though King Dahir was from Sindh from Pakistan of today we regard him as our King and though Bhagat Singh lived majorly and also was martyred at Lahore which is in Pakistan we regard him as our freedom fighter. If you visit Nepal not for one second will you feel that you are in a different culture. Likewise though a Tipu or Aurangzeb ruled on Indian kingdoms on Indian soil we cannot accept them as our Kings despite the attempts by secular parties to blend them, as they belonged to a foreign culture and represented that identity.
Our culture of India stems from the Indus Valley Civilization which spread to the Himalayas, Sapta Sindhus and the Seas hence that is what we mark as our nation.
Jai Hind Jai Akhand Bharat.
Bharat: home to greatest Spiritual Leaders of the World
Bharat: home to greatest Empires of the World
Cultural Influence of Bharat