Renato Sanches received an offer from Manchester United but opted to join Bayern Munich due to their similarities with Benfica.
The 18-year-old had reportedly been courted for a long period by the Premier League side, but his Bundesliga switch was confirmed on May 10.
Bayern stumped up an initial €35million to capture Sanches, who signed a five-year contract in a deal that could see the fee rise to €80m.
The midfielder was a Primeira Liga and Taca da Liga champion in his breakthrough season at Benfica, and it was a desire for consistency that saw him turn down United.
"Manchester United made a proposal, I think that is known," Sanches said during a promotional event.
"I chose Bayern because they are a big club and because of the similarities with Benfica.
"They have a stadium with a capacity for 65,000 people and the environment is very similar. I'm going to Bayern to win titles."
Sanches has been included in Fernando Santos' 23-man Portugal squad for Euro 2016, and, having only made two senior appearances for his country, he was not expecting to be selected.
"I tried my best for Benfica during the season and of course always had the thought of being called, but I was not expecting it," he said. "I was nervous, but it was a moment of great joy."
Santos has expressed his belief that Portugal can challenge for a first senior international title in France, and Sanches believes they have sufficient quality.
"It is normal for the coach to have ambition to win. Portugal has a great team. No one goes to the Euro to lose. We have to be focused," he added.
