It is often said that the British united India and shaped it into a country. But when we look at many of the great empires of India across history, we realize that India had been in integrated form for a long duration of time. Of course there have been smaller kingdoms and many kings controlling smaller states but it was just a matter of time before those were integrated into the form of a great empire; which often consisted of regions like Afghanistan too!
Look at the below map. This was the size of Maurya Empire around 250 years Before Christ!
The Capital of Maurya Empire was Pataliputra i.e. modern Patna in Bihar. The Maurya Empire was one of the largest empires of the world in its time.
Below is the map of Gupta Empire (गुप्त साम्राज्य); the period during which is called Golden Age in Indian History. It existed from 320 to 550 AD.
The Capital of Gupta Empire was Pataliputra i.e. modern Patna in Bihar. Samudragupta is called "Napoleon of India" for his great conquests. He conquered what is now Kashmir and Afghanistan. He was a devout Hindu and worshiped Lord Vishnu.
Btw, the Gupt Kings were not Kshatriyas by birth but were Vaishya/Bania - the same Gupta Surname which many of our friends have.
Below is the map of the Great Maratha Empire, around 1758; in orange shade. It ruled over most of Indian subcontinent in 18th and early 19th century before the British East India Company took over.
Marathas even defeated Tipu Sultan of Mysore. Peshwa Madhavrao-I defeated Hyder Ali, Tipu Sultan's father, twice in 1764 and 1767. In 1767 Peshwa Madhavrao defeated both Hyder Ali and Tipu Sultan and entered Srirangapatna, the capital of Mysore. Hyder Ali accepted the authority of Madhavrao who gave him the title of Nawab of Mysore. Tipu Sultan used to pay Rupees 1.2 million every year to Marathas who in return recognized the rule of Tipu in Mysore region.
After Marathas defeated Nizam of Hyderabad, the Nizam stopped being a force in North Indian politics and got confined to Hyderabad. Even Mughals used to pay tax to Marathas.
Marathas controlled present day Pakistan, Bangladesh as well as bordering Nepal and Afghanistan.
These were some of the great empires of India. In terms of their sheer size, these have been mammoth, often one of the biggest at their time in this world. And then there have been so many other great kingdoms, which even though smaller in size, are still remembered and venerated for many good reasons.
India has been a land of great people and great kings. A lot of people remember India only because of the spiritual light it provided to the world; and the religious tolerance Hindus practiced which was worth emulating all across the warring world. But even in terms of military might, India has not been without excellence. After all, it was India from which even the 'great' Alexander returned disappointed and empty handed!