Twickenham, situated in the southwest district of greater London from which it takes its name, has been the home of the England men's rugby union team for over a hundred years.
But from September the 82,000-seater ground will be known officially as the Allianz Stadium following a deal with the Germany-based multinational insurance company.
The failure to even include 'Twickenham' in the new title, along the lines of other sponsorship agreements such as the Emirates Old Trafford cricket ground in Manchester, has angered many rugby traditionalists.
But with Twickenham also playing host to women's and domestic rugby games, as well as pop concerts, RFU chief executive Bill Sweeney told the BBC on Tuesday: "I really don't believe we've sold out.
"It's an iconic stadium, it's the home of rugby, experiences here are incredible, people love coming here."
But with the RFU having forecast a loss of over £40 million for the 2023/24 financial year, there is no doubt English rugby union could benefit from a significant cash injection.
The naming rights deal comes with English rugby still reeling from the financial collapse of three Premiership clubs -- Wasps, Worcester and London Irish during the 2022/23 top-flight campaign.
'Legacy'
"We believe this will help us build on the legacy of the stadium," said Sweeney.
"This will take us into the future, into decades from here and the investment from Allianz will enable us to make Twickenham an even better experience for fans and players.
"We believe this is an investment into the future with the sort of partner we need to go on that journey."
The RFU has been looking for additional investment and even considered a proposal to sell Twickenham and buy a 50 percent stake in London's Wembley -- England's national football stadium.
But those plans were ditched in favour of redeveloping Twickenham at a cost of some £663 million.
Asked about how much the deal with Allianz was worth, Sweeney replied: "It's a multi-year commitment and it's well over £100 million, so it's a fair value for what you'd expect for stadium naming rights these days."
Sweeney added: "It's money that we need to invest back into the game.
"We've had a tough time coming out of Covid, the game's under pressure -- we saw three professional clubs go out of business (and) that was extremely painful.
"So, this is money we need to generate, to invest back into the community game so we keep that pipeline going."
Twickenham will now become the eighth stadium around the world to be rebranded under the Allianz banner.
The venue will host the 2025 Women's Rugby World Cup final, while the first international fixture under the new name will see England's women play world champions New Zealand on September 14.
