His reputation as a historian will chiefly rest on his _History of the Norman Conquest_ (1867-1876), his longest completed book. In common with his works generally, it is distinguished by exhaustiveness of treatment and research, critical ability, a remarkable degree of accuracy, and a certain insight into the past which he gained from his practical experience of men and institutions. He is almost exclusively a political historian. His saying that "history is past politics and politics are present history" is significant of this limitation of his work, which left on one side subjects of the deepest interest in a nation's life. In dealing with constitutional matters he sometimes attaches too much weight to words and formal aspects. This gives certain of his arguments an air of pedantry, and seems to lead him to find evidences of continuity in institutions which in reality and spirit were different from what they once had been. As a rule his estimates of character are remarkably able. It is true that he is sometimes swayed by prejudice, but this is the common lot of great historians; they cannot altogether avoid sharing in the feelings of the past, for they live in it, and Freeman did so to an extraordinary degree. Yet if he judges too favourably the leaders of the national party in England on the eve of the Norman Conquest, that is a small matter to set against the insight which he exhibits in writing of Aratus, Sulla, Nicias, William the Conqueror, Thomas of Canterbury, Frederick the Second and many more. In width of view, thoroughness of investigation and honesty of purpose he is unsurpassed by any historian. He never conceals nor wilfully misrepresents anything, and he reckoned no labour too great which might help him to draw a truthful picture of the past. When a place had any important connexion with his work he invariably visited it. He travelled much, always to gain knowledge, and generally to complete his historical equipment. His collected articles and essays on places of historical interest are perhaps the most pleasing of his writings, but they deal exclusively with historical associations and architectural features. The quantity of work which he turned out is enormous, for the fifteen large volumes which contain his _Norman Conquest_, his unfinished _History of Sicily_, his _William Rufus_ (1882), and his _Essays_ (1872-1879), and the crowd of his smaller books, are matched in amount by his uncollected contributions to periodicals. In respect of matter his historical work is uniformly excellent. In respect of form and style the case is different. Though his sentences themselves are not wordy, he is extremely diffuse in treatment, habitually repeating an idea in successive sentences of much the same import. While this habit was doubtless aggravated by the amount of his journalistic work, it seems originally to have sprung from what may be called a professorial spirit, which occasionally appears in the tone of his remarks.