Pep Guardiola will take Manchester City "to a new level", according to club chairman Khaldoon Al Mubarak.
Ex-Barcelona boss Guardiola has left Bayern Munich to replace Manuel Pellegrini as City manager this summer.
"I'm absolutely exited about Pep joining our team," said Al Mubarak. "I consider Pep to be one of, if not the best manager, in football today.
"We are getting a manager that epitomises passion and commitment. He is a proven winner."
Guardiola was victorious in the Champions League twice at Barcelona, including their treble-winning campaign in 2008-09.
He also won the German league title with Bayern for three successive seasons, although he failed to win the Champions League with the Bundesliga outfit.
Speaking to City's website, Al Mubarak added: "I have no doubt that he will transform our team to a new level."
City finished fourth in the Premier League in 2015-16 as they failed to reclaim the title they won under Pellegrini in 2014.
However, they won the League Cup and reached the Champions League semi-finals, losing to eventual winners Real Madrid.
"Over three years [under Pellegrini] we won our second Premier League title, two League Cups and got to the semi-finals of the Champions League for the first time," said Al Mubarak.
"There are a lot of achievements that have been made in those three years. We should thank Manuel and the team around him and be grateful for these achievements.
"At the same time, we also can't hide the disappointment, particularly this year. We had high expectations for this season."
Subscribe to the BSports newsletter to get our pick of news, features and video sent to your inbox.