Gasly quickly became the number one target for Alpine after Fernando Alonso announced his departure for Aston Martin and it became clear that Oscar Piastri would be joining McLaren.
Negotiations were complex because Red Bull had to confirm a replacement for Gasly at AlphaTauri, and because the drinks company put a hefty price tag on the French driver, who had one year left on his contract.
Gasly believes that Alpine is the ideal destination for him, as the team has been building up some momentum.
"The opportunity came up in the summer and we started to have conversations about it," he said. "It's obviously a big move for me, I've been with Red Bull for nine years, pretty much my entire career with them.
"It definitely feels like closing a chapter and starting on a new journey. To me, I must say, it felt natural and very quickly the right decision to take.
"Just based on where I am in my career, based on Alpine's ambition, based on their progress over the last few years. Just getting better and better every season, they have this strategy to be fighting at the front over the next 100 grands prix, and they are just going in the right direction.
"For me, it's also the right time to take off on my own, grab this opportunity with a manufacturer. I definitely believe in this project, and I'm very excited about it."
Gasly said it was key that Alpine made it clear from an early stage that he was the number one choice, and that the Enstone outfit had to work so hard to get Red Bull to release him.
"That was definitely one of the most important, let's say, criteria for me, which made it very clear for me that I should go there, is how strong their will was to get me out of Red Bull and to get me in that car.
"They made it very clear straight away they had to work very hard in terms of negotiations, it was not an easy deal to make between all parties involved.
"And it just felt like straight away they really pushed so hard to get me, and they really believe in that project."
