Background
Johann was born 31 March 1881 in Stuttgart, Germany, of German and English ancestry. He was the eldest son of The Reverend Johann Jakob Sommer (1850-1925), a Methodist preacher who was arrested and reprimanded for persistent preaching in public places, and Zillah Elizabeth Barratt (1848-1935).
He was educated in Germany, at Kingswood School, Bath, and Caius College, Cambridge, in England, and in Switzerland. From 1906 until 1912 he was a Methodist Missionary in the Ottoman Empire.
He also attended Methodist Conferences in Lausanne (1927) and in Edinburgh (1937).
He was a member of the Executive Committee of the Free Church Council of Germany. During World World War II, his family lived in the basement of their looted home, and eight times he was called before the Gestapo for questioning.