From its beginnings Christianity was characterized by a great doctrinal and ritual diversity, which caused controversies and schisms. The two most important ones were the great East-West schism separating the Orthodox from the Catholics in 1054, then the Reformation that gave birth to Protestantism in 1517.

Over the centuries some Churches split up, others merged; in the today’s world there is a wide variety of Christian Churches.

During the 20^th century an ecumenical dialogue between Christian Churches was established to promote union.