Karl Gützlaff
During his time in the Ottoman Empire, he held theological debates with local rabbis and published pamphlets on the matter in French; after facing salary disputes in Constantinople and resigning his post, Bettelheim made his way to London, where he hoped to gain authorization from the Church of England to preach to the Jewish communities of the Mediterranean. During this time, he became associated with a number of other prominent missionaries to the Far East, including Dr. Peter Parker, Karl Gützlaff, and missionary to Africa David Livingstone. Following several months of disputes with the Church of England, who refused to recognize his European degrees, insisted he study at Oxford or Cambridge, and were suspicious of someone who had so recently converted from Judaism, Bettelheim abandoned that particular quest, though he remained in London.