Leading WM educationalist, theologian, ecclesiologist and ecclesiastical statesman. He was born in Newcastle upon Tyne on 16 January 1821, the son of John Rigg (1786-1857; e.m. 1808). His maternal grandfather was James McMullen, the Irish-born missionary in Gibraltar. He was a pupil and then for four years a junior teacher at Kingswood School. After 23 years in circuit, he was Principal of Westminster College from 1868 until his retirement in 1903. From 1870 he served as a member of the first London School Board and from 1886-1888 was on the Royal Commission on Elementary Education. He strongly defended the retention of WM elementary schools against those who wanted them placed under the new School Boards. In this and other matters he was increasingly seen as out of date in the more liberal atmosphere at the turn of the century.
He vigorously defended WM against both Anglican and Congregationalist detractors. Deeply loyal to the Conference during the 1849-1851 disruption, he nevertheless advocated reform and a greater participation of the laity in church government. He was President of the Conference in 1878 and 1892. He received doctorates from Dickinson College, Pennsylvania (1865) and Edinburgh University (1877).
His studies of Wesley included The Churchmanship of John Wesley (1869) and The Living Wesley (1875). He also wrote a life of Jabez Bunting (1905). He published a volume of substantial Essays for the Times (1866) and wrote major studies of European elementary education (1873) and of comparative ecclesiology, Principles of Church Organization (1887). His Oxford High Anglicanism and its Chief Leaders (1895) was the only substantial nonconformist appraisal of the Oxford Movement.He was a frequent contributor to the Watchman and was closely involved in the editing of the London Quarterly Review from its inception in 1853.
He died at Brixton Hill, London on 17 April 1909.
His son James McMullen Rigg became a barrister and contributed articles to the Dictionary of National Biography. The younger of his two daughters married John Telford.