John Spenser Somerville (Jack) was born in 1910 at Anderson's Bay, Dunedin. He gained a Masters degree in English from the University of Otago in 1934. He then entered Knox College for three years of training at the Theological Hall of the Presbyterian Church of New Zealand, receiving his certificate of license in 1937. At Knox he met Basil Dowling, a life-long friend. From 1937 to 1938 he studied overseas, firstly at Westminster College, Cambridge and then at the University of St. Andrew's. On arrival at London he stayed with Philip Fowler, a friend from childhood until Fowler's death in 1985. Jack Somerville's first Ministry was at Tapanui in 1938. This was interrupted by active service as a chaplain in W. W. II from 1942 to 1945. He spent time in Egypt with the 3rd Tank Battalion before going on to battle at Cassino, Italy. He returned to Tapanui for the years 1946-1947. His next parish was St. Andrew's-on-the-Terrace, Wellington. He remained here from 1947 until 1963, with a year out as Moderator of the General Assembly from 1960-1961. He took interest in issues such as the "No Maoris No Tour" campaign, corporal punishment, gaming, and alcohol, and the Waterfront Strike. He gave many sermons, some of which were broadcast on the radio.
In 1964 he returned to Dunedin to be Master of Knox College. He remained Master until 1978. He gave weekly sermons to the students, In 1969 he was awarded a Doctor of Divinity Degree from the University of St. Andrew's. He had a long involvement with the University of Otago. In 1969 he was elected to the University Council. From 1970 until 1976 he was Pro-Chancellor, and Chancellor of the University from 1976 until 1982. He was involved with the appointment of the 1972 Vice-Chancellor, the Hocken Library, the University Library, the Otago University Honorary Degrees Committee, the Association of Affiliated Colleges and Halls, the Otago-Southland Tertiary Chaplaincy Trust Board and the Synod of Otago and Southland. In 1979 he became President of the Otago Early Settlers' Association. Another interest was the St. Martin's Island Community. He married Janet Macky in 1951 and they had 4 sons.