The reason for their sudden rise was the huge amount of money that Abramovich threw at signings. The fact is that any time we've had joint decisions on the football side, it has failed.
Bollicks- the reason for Chelsea's sudden rise was their policy of signing European players and managing the European way in the 90's- which is still the case. Abramovich has just continued that "policy". As I'm certain anyone of the more knowledgable posters on here will acknowlegde. Abramovich didn't come in until 2005 when they were already an established top-4 side, having had Gullit, Vialli and Ranieri who all built them into a top-4 side.
Before 1983, Chelsea had NEVER been in the 1st division. Not ever. They were were relegated again and promoted for the 2nd time in 1988. They were midtable/bottom-feeders until 1995 when they decided on a new policy to sign foreign players and had their first "foreign manager"(before any of the "top-4" and just as Wenger was signed).
This was their "sudden rise", since the other hapless English teams suddenly had to contend with a team full of foreigners and a foreign manager- something they weren't prepared for.