Which of these great Indian Empires do you know about in detail?
Yes and it is an urgent need to correct Indian History before it is late. India is a 5000 year old civilization with great Empires and with wonderful achievements but unfortunately most Indians know nothing about their glorious past and the glorification of invaders instead only ensures that generations of Indians won't feel a sense of pride about their history. An Indian should end of the day feel proud of reading our nation's 5000 year old past but that feeling is rarely instilled in the minds of Indians.
The trouble began when Congress came to power in 1947 (in a farce of democracy it was going to come to power being a British founded and funded party) and they taught history as per the agenda of their colonial reporting bosses or as per the agenda of their minority vote banks in which they painted the picture of the Hindu as a loser while portraying Congress Party members as heroes and Muslim heroes as great (in a CBSE history textbooks Chhatrapati Shivaji Maharaj is called a chieftain, not even as King whereas Mughal rulers are called Emperors). They even covered up or criticized freedom fighters or greats from their opposition parties as they criticized Veer Savarkar (Hindu Mahasabha), Bhagat Singh (Hindustan Socialist Republican Party) and Netaji Bose (who quit Congress to form Azad Hind Fouz). They even criticized Dr Ambedkar (SCF) but stopped after he became Law Minister.
2 kinds of people are underrated in contemporary India and that has been the policy since 1947 a) those who really fought against the British are ignored b) those who come in the way of Muslim appeasement in any way are ignored too.
For eg: if you rate Chhatrapati Sambhaji Maharaj highly then you will also have to downvote his killer Aurangzeb and open up and discuss the topic of the last 14 days of Chhatrapati Sambhaji in Mughal custody, which secularists will never approve of.
Also no wonder India's HRD Education Ministers from 1947 to 1975 were mostly Muslims with only one exception of Dr Shrimali, so how could they glorify Chhatrapati Sambhaji Maharaj? Also as India harped on secular values opening Chhatrapati Sambhaji Maharaj's topic was like opening a can of worms as then you must admire him as a Dharamveer which comes in the way of Muslim appeasement. Even in case of Chhatrapati Shivaji Maharaj you will find historians talking more about his secular credentials than his contribution to Hindavi Swarajya with some pseudo historians painting him as a friend of the Mughals.
The British too made it a point of preserving the legacy of those who sided with them in colonial times, so whenever you will visit Jaipur you will see very well maintained forts as Jaipur kings sided with the British whereas you will find Jodhpur forts in ruins who weren't pro British, similarly neither Chhatrapati Shivaji Maharaj's forts were well preserved nor was Shaniwarwada built by Peshwa Bajirao as they always gave tough to the British. Even Rani Laxmibai's legacy is not preserved.
Apply the above formula to all great people from history and you will see that only those are glorified whom the British or the Congress approved of in their time and till today whom the secularists approve of.