and entered at Trinity College, Cambridge, in 1818. In 1821 he was bracketed Craven scholar with Lord Macaulay and Professor Malden. He graduated B.A. in 1822 as wrangler and senior chancellor's medallist; in 1823 he was members' prizeman, and gained a fellowship over the heads of Macaulay and Malden. In 1824 he was chosen professor of ancient languages in the new university of Virginia at Charlottesville [see also under Key, Thomas Hewitt]. T. Jefferson (the president of the United States) was rector, and Long was his frequent guest. Long remained at his post for four years, but returned to England to accept the professorship of Greek in the newly founded university of London in Gower Street (afterwards University College), which was opened on 1 Oct. 1828. He held the professorship till 1831, when he became editor of the ‘Quarterly Journal of Education’ (10 vols. 1831–5), published by the Society for the Diffusion of Useful Knowledge, of whose committee Long was a most active member. He was one of the founders in 1830 of the Royal Geographical Society, was for many years a member of council, and honorary secretary from 1846 to 1848. Long had a special knowledge of geography. He contributed to volumes iii. and xii. of the Royal Geographical Society's ‘Journal,’ and to Dr. William Smith's ‘Dictionary of Greek and Roman Geography.’ He prepared the maps of Egypt and Persia for the atlas of the Society for the Diffusion of Useful Knowledge, edited ‘The Geography of America and the West Indies’ (S.D.U.K., 1841, 8vo); and wrote, with G. R. Porter, ‘The Geography of Great Britain’ (S.D.U.K. [1850?], 8vo). Long also edited an ‘Atlas of Classical Geography,’ 1854; 2nd ed. 1874; and a smaller ‘Grammar School Atlas of Classical Geography.’
From 1833 to 1846 Long was engaged on the laborious task of editing for the Society for the Diffusion of Useful Knowledge the twenty-nine volumes of the ‘Penny Cyclopædia.’ He was himself an extensive contributor and an unwearied editor, the regular issue of the monthly parts being never interrupted. He also edited and contributed to the society's ‘Biographical Dictionary’ (7 vols. 1842–4, the letter ‘A’ only). In 1842 Long became professor of Latin in University College, in succession to his great friend Thomas Hewitt Key. He resigned the chair in 1846, and for a short time was lecturer on jurisprudence and civil law in the Inner Temple. He had been called to the bar in 1837. He wrote all the articles on Roman law for Smith's ‘Dictionary of Greek and Roman Antiquities’ (1842), and published in 1847 ‘Two Discourses on Roman Law.’ In his knowledge of Roman law he stood alone among English scholars of the time, and he contributed greatly to the revival of the study of it in this country. From 1849 till midsummer 1871 Long was classical lecturer at Brighton College. He was revered and beloved by his pupils. While at Brighton he edited several school editions of the classics, and, in conjunction with Mr. Arthur J. Macleane, established and edited the ‘Bibliotheca Classica,’ contributing himself ‘Cicero's Orations’ in 4 vols., 1851–8. He also published his admirable translation of Marcus Aurelius with the title, ‘Thoughts of the Emperor M. Aurelius Antoninus’ (1862, 1869, 1879—‘Meditations,’ &c.), and began the publication of his ‘Decline of the Roman Republic,’ 5 vols. London, 1864–74, 8vo. Matthew Arnold (Essays in Criticism, ‘M. Aurelius’) praises Long for treating Roman history ‘not as a dead and dry matter of learning,’ but as having ‘a side of modern applicability and living interest.’ In 1871 Long retired to Portfield, Chichester. In 1873 he was granted a civil list pension of 100l. a year for his services to learning. The last work of his busy life was a translation of the ‘Discourses of Epictetus, with the Encheiridion and Fragments,’ 1877, 8vo. He died, aged 78, on 10 Aug. 1879, after six months' illness, and was buried in the cemetery at Portfield. Long was married three times. By his first wife, Harriet, widow of Joseph Selden, lieutenant-colonel in the United States army, he had four sons, and a daughter who died in infancy.
As a teacher and writer Long exercised much influence on classical scholarship in England. He was a man of extensive learning, gifted with a powerful memory and ‘a clear judicial intellect.’ He was even more remarkable for a rare simplicity, elevation, and integrity of life. ‘No one’ (it has been remarked) ‘ever lived the life recommended by Marcus Aurelius more completely.’
Long published, besides the writings already named: 1. ‘Tables of Comparative Etymology,’ Philadelphia, 1828, 4to (with J. Lewis). 2. ‘Introductory Lecture [on the Greek language] delivered in the University of London,’ London, 1828, 8vo. 3. ‘A Summary of Herodotus,’ 1829, 12mo. 4. ‘Observations on the Study of the Latin and Greek Languages,’ London, 1830, 8vo. 5. ‘Herodotus,’ Greek text, 1830–3, 8vo; 1838, 1848, 1851. 6. Xenophon's ‘Anabasis,’ 1831, 1837, 1848, 8vo. 7. ‘Egyptian Antiquities’ (in the British Museum), S.D.U.K., 1832, &c. 12mo. 8. ‘Grammar Schools,’ a treatise in C. Knight's ‘Store of Knowledge’ , 8vo. 9. ‘The Civil Wars of Rome’ (select