Mommensen, THEODOR, the most learned historian of Rome, was born the son of a pastor at Garding, in Sleswick, 30th November 1817. He studied at Kiel, next spent three years traversing France and Italy in the study of Roman inscriptions under commission of the Berlin Academy, edited awhile the Schleswig-Holsteinische Zeitung, and in the autumn of 1848 was appointed to a chair of Jurisprudence at Leipzig, of which two years later he was deprived for the part he took in politics. In 1852 he was appointed to the chair of Roman Law at Zurich, in 1854 at Breslau, and in 1858 to that of Ancient History at Berlin. Here he was engaged for many years in editing the monumental Corpus Inscriptionum Latinarum, projected by the Berlin Academy, and commenced in 1863; and in 1873 he was elected perpetual secretary of the Academy. In 1882 he was tried for slandering Bismarck in an election speech, but was cleared both in the lower court and in that of appeal. His fine library was burned in 1880, whereupon a number of English students presented him with a collection of books to make good at least part of his loss. Mommensen took a share in the work of editing the Monumenta Germaniæ Historica, and has made his name illustrious by a series of works of vast range and profound erudition. His greatest work remains his Römische Geschichte, brought down to the battle of Thapsus (3 vols. 1854–56; 8th ed. 1889; Eng. trans. by W. P. Dickson, 4 vols. 1862–67). These three volumes form books i.–v. of Mommensen's plan; vol. v., forming book viii., was issued in 1885 (Eng. trans. by Dickson, The Provinces of the Roman Empire from Cæsar to Diocletian, 2 vols. 1886). Freeman characterises Mommensen as 'the greatest scholar of our times, well-nigh the greatest scholar of all times . . . language, law, mythology, customs, antiquities, coins, inscriptions, every source of knowledge of every kind—he is master of them all.' But, while admitting readily his wide and sure grasp of historical sequence, the reader finds Mommensen defective in political and moral insight, and prone to fall down in worship before mere force and success.
Other important works of Mommensen's are Oskische Studien (1845); Die Unteritalischen Dialekte (1850); Corpus Inscriptionum Neapolitanarum (1851); his monographs on Roman Coins (1850); the edict of Diocletian, De Pretiis Rerum Venalium (1851); Die Rechtsfrage zwischen Cæsar und dem Senat (1857); Römische Forschungen (1864–79); Res Gestæ Dîvi Augusti (1865); Römisches Staatsrecht (1871–76; 3d ed. 1887); and his Digesta Justiniani Augusti (1866–70).
Of his brothers, two have achieved distinction: TYCHO, born at Garding, 23d May 1819, studied at Kiel, traversed Italy and Greece, and held educational appointments at Eisenach, Oldenburg, and Frankfurt-on-Main until his retirement in 1885. He devoted many years to studies upon Pindar, producing a great critical edition in 1864 (an edition of the text in 1866), Scholica (1861), a translation (1846), and Parerga Pindarica (1877).
AUGUST, born at Oldesloe, 25th July 1821, studied at Kiel, and taught in schools at Hamburg, Parchim, and Sleswick. Most of his works belong to the field of Greek and Roman chronology. Among them are Römische Daten (1855), Beiträge zur Griechischen Zeitrechnung (1856–59), Griechische Jahreszeiten (1873), Delphika (1878), and Chronologie Untersuchungen über das Kalenderwesen der Griechen (1883).