Chelsea owner Roman Abramovich has lifted the standard of the Premiership, says chief executive Peter Kenyon.
He said: "It has been five years of unbelievable change and achievement at Chelsea.
"It has been the most successful period regarding trophies in the history of the club. We have won back-to-back Premierships, cups and a first-ever Champions League Final. But also the hold of Manchester United and Arsenal was broken and we have attracted some of the world's best players to Chelsea, and therefore to the Premier.
"Our main rivals have had to respond to the situation. Things have become more competitive and that can only be a good thing for the Premier League."