Passage: In July 2003, Bates sold Chelsea to Russian billionaire Roman Abramovich for £140 million. Over £100 million was spent on new players, but Ranieri was unable to deliver any trophies, and was replaced by José Mourinho. Under Mourinho, Chelsea became the fifth English team to win back-to-back league championships since the Second World War (2004–05 and 2005–06), in addition to winning an FA Cup (2007) and two League Cups (2005 and 2007). After a poor start to the 2007–2008 season, Mourinho was replaced by Avram Grant, who led the club to their first UEFA Champions League final, which they lost on penalties to Manchester United.

Question: Who purchased Chelsea in 2003?
Roman Abramovich