Complex sentence: It is one of the most important examples of the Gothic architectural tradition of the 12th and 13th centuries, dating earlier than the cathedrals of Sens and Notre Dame of Paris and ranking with them in importance.
Split into simpler sentences: It is one of the most important examples of the Gothic architectural tradition of the 12th and 13th centuries. However, the church predates the cathedrals of Sens and Notre Dame of Paris, ranking with them in importance.