September 25, 1712, Kunnewald (near Fulnek), Moravia.
June 30, 1783, Sarepta on the Volga, Russia.
Johann was the brother of hymnist Anna Nitschmann.
He went to the Moravian settlement at Herrnhut in 1725. In 1726, Count von Promnitz took him into the orphanage at Sorau, and in 1728 sent him to study theology at Halle.
In 1731, he became a tutor to the orphanage at Herrnhut, then in 1732 went to Halle to study medicine, but returned to Herrnhut in 1733, and spent a year as private secretary to Zinzendorf.
Thereafter, up to 1745, he was principally engaged in mission work in Swedish Lapland, and in forming communities in Livonia. In 1745, he was appointed diaconus and Gemeinhelfer at Herrnhaag, Wetteravia, and in 1750 to the same position at Herrnhut.
He became bishop of the Brethren’s Unity in 1758, and in 1761 superintendent of the communities in England and Ireland. In 1766, he was put in charge of the new settlement of Sarepta on the Volga, Russia.