Ashutosh Gowariker was first inspired to someday make a film set in the ancient Indus Valley civilization way back when he was in Bhuj, Gujarat, scouting locations for his then-upcoming Lagaan: Once Upon a Time in India (2001), and stumbled across the massive excavations in progress at the ruins of Dholavira.
Professor Jonathan Mark Kenoyer, widely considered as one of the world's leading experts on the ancient Indus Valley civilization, visited Bhuj to inspect and approve the sets and props built by the filmmakers.
Ashutosh Gowariker's wife and co-producer Sunita Gowariker was confused as to how her husband would shoot the film as the historical city is in ruins, so he told her that they will have to create the sets.
Ashutosh Gowariker took three years to research and piece together a plot of the entire civilization through various cities and weave a love story into it. He met as many as seven archaeologists who are closely involved in excavating sites and studying the Indus Valley Civilization and came up with a 300 page script which he then reduced to 80 pages to get Hrithik Roshan to accept the lead role.