Complex sentence: From 1999 on, the "Prince of the Carnival" event was introduced with the enthronement of the Prince that takes place on 11 November (St. Martin's Day), which has become an important cultural and entertaining event in itself.
Split into simpler sentences: From 1999 on, the Prince of the Carnival event was introduced with the enthronement of the Prince that takes place on 11 November (St. Martin's Day). This has become an important cultural and entertaining event in itself.