See A. F. Stanley, The Life and Correspondence of Thomas Arnold, D.D. (1844); A. Whitridge, Dr. Arnold of Rugby (1928); N. G. Wymer, Dr. Arnold of Rugby (1953, repr. 1970); T. W. Bamford, Thomas Arnold (1960); M. Trevor, The Arnolds (1973).
Arnold was born on the Isle of Wight, the son of William Arnold, an inland revenue officer, and his wife Martha de la Field. He was educated at Winchester and Corpus Christi College, Oxford. There he excelled at Classics and was made a fellow of Oriel in 1815. His appointment to the headship of Rugby, the famous public school, after some years as a tutor, turned the school's fortunes around, and his force of character and religious zeal enabled him to turn it into a model followed by the other public schools, exercising an unprecedented influence on the educational system of the country. He is portrayed as a leading character in the novel, Tom Brown's Schooldays.
He was involved in many controversies, educational and religious. As a churchman he was a decided Erastian, and strongly opposed to the High Church party. In 1841, he was appointed Regius Professor of Modern History at Oxford. His 1833 Principles of Church Reform is associated with the beginnings of the Broad Church movement. He was also one of the Eminent Victorians in Lytton Strachey's book of that name.
His chief literary works are his unfinished History of Rome (three volumes 1838-42), and his Lectures on Modern History. He died suddenly of a heart attack in the midst of his growing influence. His biography, Life of Arnold, by Arthur Penrhyn Stanley, one of Arnold's former pupils, is considered one of the best works of its class in the language.
Thomas the Younger's daughter Mary Augusta Arnold, became a famous novelist under her married name of Mrs Humphry Ward, whilst Tom's other daughter married Leonard Huxley (writer), the son of Thomas Huxley and their sons were Julian and Aldous Huxley.
A more recent public school headmaster, Michael McCrum of Tonbridge and Eton in the 1960s through 1980s, and also a churchman and Oxbridge academic (Master of Corpus Christi College, Cambridge and Vice-Chancellor), wrote a biography and reappraisal of Arnold in 1991. McCrum was steeped in the significance of Rugby and of public schools; he too had briefly been a master at Rugby and was married to the daughter of another former headmaster.
More recently, a biography entitled Black Tom has been written by Terence Copley. Both McCrum and Copley have sought to restore some of the lustre to the Arnold legacy which has been heavily under attack since Strachey's sardonic appraisal.