Complex sentence: Pays d'Aix RC is a French rugby union club which will play the upcoming 2009--10 season in Pro D2, the second tier of the country's professional system, after earning promotion from the top amateur league, Fédérale 1.
Split into simpler sentences: Pays d'Aix RC is a French rugby union club currently playing in Pro D2, the second tier of the country's professional system. They arrived in Pro D2 for the 2009--10 season after earning promotion from the top amateur league, Fédérale 1.