Manchester United chief executive Ed Woodward has branded Louis van Gaal "one of the outstanding managers in the game today" after the current Netherlands boss was appointed as the new manager of the club.
Van Gaal, who has signed a three-year contract, will officially take up his post after the World Cup this summer.
"In Louis van Gaal, we have secured the services of one of the outstanding managers in the game today. He has achieved many things in his career to date and Old Trafford provides him with a fitting stage on which to write new chapters in the Manchester United story," he told the club's official website.
"Everyone is very excited about this new phase in the club's history. His track record of success in winning leagues and cups across Europe throughout his career makes him the perfect choice for us.
"People know him as a larger than life character but I have also been extremely impressed by his intelligence, thoughtful approach to the role and his diligence. I'm looking forward to working with him."
"I'm delighted that Louis has chosen Ryan as his assistant. Ryan's association with the club spans over two decades and his knowledge and stature will be of great use to Louis. In addition, this is a fantastic opportunity for Ryan to learn his trade alongside a world-class manager whose attacking instincts and belief in youth are tailor-made for Manchester United."
Ryan Giggs, meanwhile, has been officially named as the club's new assistant manager.