Complex sentence: During the Calles administration, oppression against the Catholic Church greatly expanded in 1926 under the Calles Law, which provided severe penalties for priests and individuals who violated the provisions of the 1917 Constitution.
Split into simpler sentences: During the Calles administration, oppression against the Catholic Church greatly expanded in 1926 under the Calles Law. This law provided severe penalties for priests and individuals who violated the provisions of the 1917 Constitution.