Herrnhut grew rapidly following this transforming revival and became the centre of a major movement for Christian renewal and mission during the 18th century. The episcopal ordination of the Ancient Unitas Fratrum was transferred in 1735 to the Renewed Unitas Fratrum by the Unity's two surviving bishops, Daniel Ernst Jablonski and Christian Sitkovius. The carpenter David Nitschmann and, later, Count von Zinzendorf, were the first two bishops of the Renewed Unity. Moravian historians identify the main achievements of this period as: