Complex sentence: On 12 June in 1096, Pope Urban II visited the town and blessed the stones used to build the cathedral of Saint Nazaire and Saint Celse; construction was completed in the first half of the twelfth century.
Split into simpler sentences: On 12 June 1096, Pope Urban II visited the town and blessed the stones used to build the cathedral of Saint Nazarius and Saint Celsus. Construction was completed in the first half of the twelfth century.