In 1928, an agreement was forged between the senior overseers that limited workers operating outside of their appointed geographical spheres, known as "fields": workers traveling into an area controlled by another overseer had to first submit their revelation to, and obtain permission from, the local overseer. The exact boundaries between fields was worked out over time, and there were areas where workers under the control of more than one overseer operated, causing conflict. During the First World War, the church obtained exemption from military service in Britain under the name "The Testimony of Jesus". However, there were problems with recognition of this name outside the British Isles, and exemption was refused in many other areas. In New Zealand during World War I, members of the church could not prove their conscientious objector status, and formed the largest segment of those imprisoned for refusal to serve. Members and ministers also had difficulty establishing their conscientious objector status in the United States during the First World War. With the start of the Second World War, formal names were adopted and used in registering the church with various national governments. These names continued to be used for official business, and stationery bearing those names was printed for the use of overseers. Most members were not aware of these names. Some who dissented after learning of the practice were expelled by the workers. After the death of Australian overseer William Carroll in 1953, an attempt was made to reintegrate the repudiated adherents of William Irvine and Edward Cooney. Rather than producing further unity, the attempt produced conflicts over the church's history which was exposed, the existence of legal names, disagreements over the hierarchy which had developed and other controversies. Many excommunications took place in the subsequent effort to enforce harmony. The earliest workers and overseers were succeeded by a new generation of leaders. In Europe, William Irvine died in 1947, Edward Cooney died in 1960, and John Long (expelled in 1907) died in 1962. British overseer Willie Gill died in 1951. In the South Pacific, New Zealand overseer Wilson McClung died in 1944, and Australian overseer John Hardie died in 1961. In North America, both Jack Carroll, the Western overseer, and Irvine Weir died in 1957 while Eastern overseer George Walker died in 1981. Its policy of not revealing its name, finances, doctrine or history, and avoidance of publicity largely kept the church from