Complex sentence: In the early Middle Ages the Christian Church ignored homosexuality in secular society; however, by the end of the 12th century hostility towards homosexuality began to emerge and spread through Europe's secular and religious institutions.
Split into simpler sentences: In the early Middle Ages the Christian Church ignored homosexuality in secular cultures outside the Church. However, by the end of the 12th century hostility towards homosexuality began to emerge and spread through Europe's secular and religious institutions.