A gem-encrusted tiger's head from the throne of Tipu Sultan - the Indian king famed for resisting British rule - is due to be sold in the UK next month.
The sale takes place less than a month after personal possessions of the Indian independence leader, Mahatma Gandhi, were sold in the US.
Auctioneers Bonhams say the head is one of the most important Tipu Sultan belongings to be sold.
It had been left undiscovered in an English castle for at least 100 years.
The tiger's head is a finial - or decorative piece - from the octagonal golden throne of Tipu Sultan, the "Tiger of Mysore", and is valued at about $1,169,278 (£800,000). It is due to be sold at Bonhams in London on 2 April.
Correspondents say that the auction is bound to be controversial in India, where the recent sale of Gandhi's spectacles, pocket watch, sandals and other personal items in New York was not well received.
A Bonhams official told the BBC that the company did not expect the sale to generate the same uproar as the auction of the Gandhi artefacts, because the finial had been in British hands since 1800 and because two more valuable pieces from Tipu Sultan's throne form part of the British royal collection at Windsor Castle.
The finial was discovered by experts from the Islamic department of Bonhams on a routine valuation at Featherstone Castle in the north of England. It was kept there for many years being being deposited in a bank vault. The castle is the home of Baron Wallace of Knarsdale, who oversaw the East India Company.
The Gandhi items were bought by Kingfisher beer tycoon Vijay Mallya, for $1.8m - 60 times the expected price - after the Indian government, the Gandhi family and even the seller tried to stop the auction from going ahead.
Mr Mallya is also known to have a keen interest in Tipu Sultan - buying Tipu Sultan's sword for $472,292 (£350,000) at an auction in London in 2003 and famously brandishing it at an election campaign rally.
However, he told The Times newspaper in Britain that he was not interested in bidding for the tiger's head as it was only a small part of a larger piece.
Tipu Sultan is considered to be one of the most accomplished and daring rulers of pre-colonial India, devising campaigns which inflicted humiliating defeats on the British.
He is credited with introducing the rocket to attack enemy infantry, a tactic that helped him win a number of victories over British armies, proving that they were not invincible.
"It is without a doubt of the greatest historical significance as it belongs to the most important symbolic object in Tipu Sultan's kingdom, his throne, which he refused to mount until he had defeated the British," said Claire Penhallurick of Bonhams Indian and Islamic department.