Complex sentence: In 2009--10 that elusive promotion to the twelve-team Premier League was finally achieved and the Fed maintained their Premier status by finishing eighth at the end of the 2010--11 season.
Split into simpler sentences: In 2009--10 that elusive promotion to the twelve-team Premier League was finally achieved. The Fed maintained their cherished Premier status by finishing eighth at the end of the 2010--11 season.