Unless you have been living on Mars and have just started watching football, then you will be aware of Chelsea's turn of fortunes since 2003.
This is due mostly to one man, Roman Abramovich.
Chelsea have had their ups and downs in their 107-year history, battling against relegation on a couple of occasions.
But since the Russian billionaire's takeover of the club, Chelsea have become one of the biggest football clubs in Europe.
With billionaires you get money (billions of it), and this has helped Chelsea become a worldwide brand by bringing in the best players from all over the world.
Chelsea fans are now used to winning, which wasn't always the case, so fans who have followed the club for years are really enjoying the Roman Abramovich era.
There are still fans of certain clubs who haven't been successful for a while (not mentioning any names) that say Chelsea have no history, but under Roman Abramovich Chelsea are making their own history right now.
But what are the main reasons Blues fans should be thanking the Russian, and what has be brought to the club?