Winger Ashley Young has signed for Manchester United from Premier League rivals Aston Villa on a five-year deal.
The 25-year-old, reported to have cost United about £17m, passed his medical with the league champions on Thursday.
"The opportunity to come to play for one of the biggest clubs in the world is one I couldn't turn down," the former Watford player told MUTV.
"It is a chance to hopefully become part of history by helping them to win their 20th title."
Young had been at Villa for more than four years after joining from the Hornets but only had one year left on his contract.
He becomes the club's second signing of the summer following the arrival of Phil Jones with Watford set to get 15% of any figure above the £9.65m transfer fee Villa paid to take him from Vicarage Road.
A new goalkeeper also remains on manager Sir Alex Ferguson's shopping list to replace Edwin van der Sar, with Atletico Madrid's David de Gea tipped to take the number one jersey.
Young began his professional career at Watford and made his first-team debut in 2003. He shone for the club during the 2005/2006 season and helped them achieve promotion after they beat Leeds United in the play-off final.
In January 2007, Young signed for Villa, where he scored 38 goals in 190 appearances, and later that year finally made his England debut as a substitute in the friendly against Austria.
He now hopes to establish himself at Old Trafford, but admits it will be a challenge to earn a regular spot in Ferguson's starting XI.
"There's a lot of competition for places at the club," he added. "If you are in the team there is always going to be someone biting away at your heels trying to get in.
"I'm going to be coming in looking to establish myself in the team. I know it is going to be a challenge, but I'm up for that challenge.
"It is a fantastic team. The club always produces fantastic players. They have that winning mentality.
"I hope to be a part of that this season. I can't wait to get started.
"It is a prospect I always looked at from being a child - to play for one of the biggest clubs in the world. I've got that opportunity now so I've just got to take it with two hands."
United and England team-mate Rio Ferdinand was one of the first to respond to the arrival of Young at Old Trafford.
"Welcoming Ashley Young to Manchester United - another top, hungry and young player joins the ranks," he stated on his Twitter page.
Wayne Rooney welcomed the winger and believes he will soon be helping to create plenty of goals at Old Trafford.
He said on Twitter: "Nice to see Ash Young sign today. Great player. Looking forward to some assists off him."
And fellow striker Michael Owen added on Twitter: "Great to hear the Ashley Young deal has been finalised. Great addition to the squad."
Aidy Boothroyd, Young's former manager at Watford, said the winger would benefit from the prospect of playing for Ferguson's team.
"He is a wiry little thing and he hasn't grown very much since he left Watford," Boothroyd told BBC Sport.
"He is very talented and was always willing to practice certain aspects of his game. He is a brilliant team player and so athletically gifted. Even when he wasn't having a great game, he was capable of changing a game with a goal or creating one for a team-mate.
"The move to Old Trafford will do him the world of good. It is a move that will stretch him again, but he has the character to handle the next stage."
Peter Taylor, who gave Young his England Under-21 debut, said that midfielder would prove to be an invaluable asset for United.
"He will offer United real attacking adaptability and options," added the former England coach.
"Ashley showed last season he can play in a couple of positions, he is tremendous at set-pieces and scores and creates goals. He provides an end product and he will get plenty of opportunities to do that at Old Trafford."
Meanwhile, BBC Match of the Day analyst Mark Lawrenson also thinks Young and United will suit each other perfectly.
"He is playing for a manager in Ferguson who loves wide players and who loves to throw people forward so he should be right at home," Lawrenson told BBC Sport. "Young also had a great record of assists at Villa and you can be sure he will have more at United because he will have so much more of the ball."