Complex sentence: Lusitanos XV are a Portuguese professional rugby union representative team based in Lisbon which was created in September 2013 to compete in the 2013--14 European Challenge Cup.
Split into simpler sentences: Lusitanos XV are a Portuguese professional rugby union representative team based in Lisbon that competes in the European Challenge Cup competition. The side was created in September 2013 to compete in the 2013--14 European Challenge Cup.