BRDC president Damon Hill admitted he feared for the future of the British Grand Prix before a deal was completed to secure the race at Silverstone from next year.
Formula 1 boss Bernie Ecclestone began talks with the BRDC after Donington, who had a deal to host the race from 2010, failed to complete its redevelopment work.
Hill said a deal was hard to reach and conceded there were moments of doubt.
"No. I think it was too easy to assume that this would naturally fall into place," Hill said when asked if he was confident the deal would come off.
"We have been through many twists and turns with the Donington Park episode and so forth, but it was never a done deal, it was never a foregone conclusion, and it was very important to make it clear that Silverstone had to sign up to a deal which was manageable and not something that was pie in the sky."
Hill admitted the 17-year deal was very important for the BRDC.
"It is immeasurable. You cannot really put your finger on it," he added.
"The BRDC and Silverstone have been absolutely mindful of the effect of the British Grand Prix on the industry in this country, which placed it in a difficult situation because they also had to think of their obligations to their own property and their own business. So it had to be a deal that was doable.
"It was a tough deal to fulfil, there is no question of that, but it is a commitment. And this is a point where we have moved into a new realm where we are committed to developing Silverstone and making big investments into the circuit for not just the benefit of Silverstone but for keeping the grand prix for the fans and the competitors."
And the former world champion is sure Ecclestone will still push Silverstone hard despite having agreed such a long-term deal.
"Bernie is a driven man and he always want better. I am sure he will be looking to keep us on our toes!"