Complex sentence: The 2006--07 season also marked the 100th anniversary of the first game to be held at their St Andrew's stadium, and saw Birmingham promoted back to the Premier League after just one season in The Championship.
Split into simpler sentences: The 2006--07 season also marked the 100th anniversary of the first game to be held at their St Andrew's stadium. The season saw Birmingham promoted back to the Premier League after just one season in The Championship.