Born in Paris, of Breton descent, after studying at the École Normale Supérieure he was sent to the French school at Athens in 1853, he directed some excavations in Chios, and wrote an historical account of the island. After his return he filled various educational offices, and took his doctor's degree with two theses, Quid Vestae cultus in institutis veterum privatis publicisque valuerit and Polybe, ou la Grèce conquise par les Romains (1858). In these works his distinctive qualities were already revealed. His minute knowledge of the language of the Greek and Roman institutions, coupled with his low estimate of the conclusions of contemporary scholars, led him to go direct to the original texts, which he read without political or religious bias. When, however, he had succeeded in extracting from the sources a general idea that seemed to him clear and simple, he attached himself to it as if to the truth itself, employing dialectic of the most penetrating, subtle and even paradoxical character in his deduction of the logical consequences. From 1860 to 1870 he was professor of history at the faculty of letters at Strasbourg, where he had a brilliant career as a teacher, but never yielded to the influence exercised by the German universities in the field of classical and Germanic antiquities.
It was at Strasbourg that he published his remarkable volume La Cité antique (1864), in which he showed forcibly the part played by religion in the political and social evolution of Greece and Rome. The book was so consistent throughout, so full of ingenious ideas, and written in so striking a style, that it ranks as one of the masterpieces of the French language in the 19th century. By this literary merit Fustel set little store, but he clung tenaciously to his theories. When he revised the book in 1875, his modifications were very slight, and it is conceivable that, had he recast it, as he often expressed the desire to do in the last years of his life, he would not have abandoned any part of his fundamental thesis. The work is now largely superseded.
Fustel de Coulanges was the most conscientious of men, the most systematic and uncompromising of historians. Appointed to a lectureship at the École Normale Supérieure in February 1870, to a professorship at the Paris faculty of letters in 1875, and to the chair of medieval history created for him at the Sorbonne in 1878, he applied himself to the study of the political institutions of ancient France. The invasion of France by the German armies during the Franco-Prussian War attracted his attention to the Germanic invasions under the Roman Empire. Pursuing the theory of JB Dubos, but singularly transforming it, he maintained that those invasions were not marked by the violent and destructive character usually attributed to them; that the penetration of the German barbarians into Gaul was a slow process; that the Germans submitted to the imperial administration; that the political institutions of the Merovingians had their origins in the Roman laws at least as much as, if not more than, in German usages; and, consequently, that there was no conquest of Gaul by the Germans. This thesis he sustained brilliantly in his Histoire des institutions politiques de l'ancienne France, the first volume of which appeared in 1874. It was the author's original intention to complete this work in four volumes, but as the first volume was keenly attacked in Germany as well as in France, Fustel was forced in self-defence to recast the book entirely. With admirable conscientiousness he re-examined all the texts and wrote a number of dissertations, of which, though several (e.g. those on the Germanic mark and on the allodium and beneficium) were models of learning and sagacity, all were dominated by his general idea and characterized by a total disregard for the results of such historical disciplines as diplomatic. From this crucible issued an entirely new work, less well arranged than the original, but rich in facts and critical comments. The first volume was expanded into three volumes, La Gaule romaine (1891), L'Invasion germanique et la fin de l'empire (1891) and La Monarchie franque (1888), followed by three other volumes, L'Alleu et le domaine rural pendant l'époque mérovingienne (1889), Les Origines du système féodal: le bénéfice et le patronat ... (1890) and Les Transformations de la royauté pendant l'époque carolingienne (1892).
Thus, in six volumes, he had carried the work no farther than the Carolingian period. The result of this enormous labour, albeit worthy of a great historian, clearly showed that the author lacked all sense of historical proportion. He was a diligent seeker after the truth, and was perfectly sincere when he informed a critic of the exact number of "truths" he had discovered, and when he remarked to one of his pupils a few days before his death, "Rest assured that what I have written in my book is the truth." Such superb self-confidence can accomplish much, and it undoubtedly helped to form Fustel's talent and to give to his style that admirable concision which subjugates even when it fails to convince; but a student instinctively distrusts an historian who settles the most controverted problems with such impassioned assurance. The dissertations not embodied in his great work were collected by himself and (after his death) by his pupil, Camille Jullian, and published as volumes of miscellanies: Recherches sur quelques problèmes d'Histoire (1885), dealing with the Roman colonate, the land system in Normandy; the Germanic mark, and the judiciary organization in the kingdom of the Franks; Nouvelles recherches sur quelques problèmes d'histoire (1891); and Questions historiques (1893), which contains his paper on Chios and his thesis on Polybius.
His life was devoted almost entirely to his teaching and his books. In 1875 he was elected member of the Académie des Sciences Morales, and in 1880 reluctantly accepted the post of director of the École Normale. Without intervening personally in French politics, he took a keen interest in the questions of administration and social reorganization arising from the fall of the imperialist régime and the disasters of the war. He wished the institutions of the present to approximate more closely to those of the past, and devised for the new French constitution a body of reforms which reflected the opinions he had formed upon the democracy at Rome and in ancient France. But these were dreams which did not hold him long, and he would have been scandalized had he known that his name was subsequently used as the emblem of a political and religious party. He died at Massy (Seine-et-Oise) in 1889.
Throughout his historical career--at the École Normale and the Sorbonne and in his lectures delivered to the empress Eugénie--his sole aim was to ascertain the truth, and in the defence of truth his polemics against what he imagined to be the blindness and insincerity of his critics sometimes assumed a character of harshness and injustice. But, in France at least, these critics were the first to render justice to his learning, his talents and his disinterestedness.