FLACH, GEOFFROI JACQUES French jurist and historian, was born at Strasbourg. After the war of 1870 he settled in Paris. In 1884 he succeeded Edouard Laboulaye at the College de France in the chair of comparative legislation.
His great work, Les Origines de l'ancienne France, was pro duced slowly. Its three volumes—Le Regime seigneurial (1886), Les Origines communales, la f eodalite et la chevalerie (1893) and La Renaissance de l'etat (1904)—appeared at long intervals, and are not always in complete harmony, but they are marked by originality and vigour. Flach gave them a solid basis by the wide range of his researches, utilizing charters and cartularies (published and unpublished), chronicles, lives of saints and even those dangerous guides, the chansons de geste. He pursued the same method in his L'Origine de l'habitation et des lieux habites en France (1899), in which he discusses some of the theories circulated by A. Meitzen in Germany and by Arbois de Jubain ville in France. Following in the footsteps of the jurist F. C. von Savigny, Flach studied the teaching of law in the middle ages and the Renaissance, and produced Cujas, les glossateurs et les Bartolistes (1883), and Etudes critiques sur l'liistoire du droit romain au moyen age, avec textes inedits (1890.