The Broncos are to become known as Harlequins Rugby League and will move into the newly-christened Twickenham Stoop for the start of the 2006 engage Super League season.
They will adopt Harlequins' famous pastel colours and the jester logo for their fourth incarnation since the club was founded as Fulham RFLC in 1980.
But far from seeing this as the first step to rugby league's identity being erased in the capital, officials from both clubs are confident it will go from strength to strength.
"This is great for the future of the club," said Broncos head coach Tony Rea.
"You have to say it's the start of something that is very special. It has worked here before and I think it can work even better.
"Take the work ethic and the standards of the club and add the history that Quins bring and it will be fantastic.
"We want to be seen as brothers. Both codes can work together very well. You'd be a bit of a dope if you couldn't learn something off each other. It will be challenging but it's an opportunity."
The partnership brings London's two professional rugby clubs together under the same umbrella and makes commercial and economic sense for both parties.
The Broncos, relaunched earlier this year after being forced into liquidation with €4.3 million of debt, were desperate to find a permanent home that would allow them to develop a firm financial footing.
They may have had to sacrifice their name and colours to find it, but new chairman Ian Lenegen believes the club will be in a position to break even by the end of next season.
Harlequins RL will pay no rent for the ground and will receive every penny from bar, hospitality and merchandise receipts on their match days a situation they never enjoyed before during their nomadic history.
The deal also enhances Harlequins' positive approach to life following their relegation from the Premiership last season.
Chief executive Mark Evans has not only worked hard to retain the majority of his Premiership squad but he has recruited Dean Richards as director of rugby and New Zealand international fly-half Andrew Mehrtens to spearhead their promotion push.
And he rejected suggestions the deal had been struck to bolster Harlequins finances following relegation.
"It was an idea I was knocking about in the late nineties. I always thought there might be an opportunity here. If you think I only did it for a few bob you are wrong. It has got to be right for both sides," Evans said.