India should "take revenge" for its painful history of attacks and subjugation, national security adviser Ajit Doval said on Saturday.

“You are lucky that you were born in an Independent India. I was born in a colonised India,” Doval, 81, told a gathering of 3,000 young delegates from across the country at the opening ceremony of the Viksit Bharat Young Leaders Dialogue in Delhi.

“Our ancestors fought for independence, they went through so many trials and tribulations," he said, speaking in Hindi.

Doval, the guest of honour at the event, mentioned the struggles and sacrifices of freedom fighters like Mahatma Gandhi, Subhash Chandra Bose and Bhagat Singh to drive home his point.

"People like Bhagat Singh were hanged, Subhash Chandra Bose struggled all his life and Mahatma Gandhi had to do satyagraha for us to gain Independence," he said.

“All the struggles and wars going on around the world are because some countries want to impose their own will on others and are using all their power for it. But if you are powerful, you will remain free. If there is no self-confidence, then all the power and ammunition are useless,” he said.

“We are fortunate to have such leadership in our country today,” he said.

Without naming Prime Minister Narendra Modi, Doval added: “His commitment, dedication, and hard work are an inspiration for all of us. As Napoleon once said, ‘I am not afraid of 1,000 lions led by a sheep, but of 1,000 sheep led by a lion.’”

At one point, Doval said: "We were a progressive society. We did not attack other civilisations or their temples, but since we were not self-aware when it came to security, history taught us a lesson.

“Countless people lost their lives. Our temples were destroyed, villages were looted, and our civilisation was crushed, while we remained helpless, mute spectators. History challenges us. Today’s youth has that fire. Although revenge is not a good word, it is powerful. We must take revenge for our country by rebuilding a great Bharat based on our values,” he said.

What the former Intelligence Bureau chief said about attacking others and destroying places of worship, however, has been contested by many historians.

For example the late D.N. Jha, an expert on ancient and medieval history, in his book Against the Grain: Notes on Identity, Intolerance and History had sharply critiqued what he called "Hindutva ideologues" who look at ancient India as "a golden age marked by social harmony, devoid of any religious violence.”

Jha provided historical evidence, including of the destruction of Buddhist stupas, to argue his point.

"Demolition and desecration of rival religious establishments, and the appropriation of their idols, was not uncommon in India before the advent of Islam," he wrote. "Evidence for such destruction dates as far back as the end of the reign of Ashoka, who is credited with making Buddhism a world religion.”

Also, the Cholas did invade other lands, including present-day Sri Lanka, the Maldives, Indonesia, Malaysia and Thailand.

And although Jha blamed “Hindutva ideologues”, the vision of India of the past as one of tolerance and cosmopolitanism was largely made famous by a man the current ruling dispensation in India loves to hate – the country’s first prime minister, Jawaharlal Nehru.