His first continuous studies had lain among the Angevin kings of England, and the note-books still exist in which he had accumulated materials for their history. However, the book he planned was never written, for when the state of his lungs (which forced him to spend the winter of 1870-71 at San Remo) had begun to alarm his friends, they urged him to throw himself at once into some treatise likely to touch the world more than a minute account of so remote a period could do. Accordingly he began, and in two or three years, his winters abroad sadly interrupting work, he completed the _Short History of the English People_. When a good deal of it had gone through the press, he felt, and his friends agreed with him, that the style of the earlier chapters was too much in the eager, quick, sketchy, "point-making" manner of his _Saturday Review_ articles, "and did not possess" (says the friend whom I have already quoted) "enough historical dignity for a work which was to take in the whole history of England. It was then, being convinced of this, that he cancelled a great deal of what had been stereotyped, and re-wrote it, re-creating, with his passionate facility, his whole style." In order to finish it he gave up the _Saturday Review_ altogether, though he could ill spare what his writing there brought him in. It is seldom that one finds such swiftness and ease in composition as his, united to so much fastidiousness. He went on remoulding and revising till his friends insisted that the book should be published anyhow, and published it accordingly was, in 1874. Feeling that his time on earth might be short, for he was often disabled even by a catarrh, he was the readier to yield.
The success of the _Short History_ was rapid and overwhelming. Everybody bought it. It was philosophical enough for scholars, and popular enough for schoolboys. No historical book since Macaulay's _History_ has made its way so fast, or been read with so much avidity. And Green was under disadvantages from which his great predecessor did not suffer. Macaulay's name was famous before his _History of England_ appeared, and Macaulay's scale was so large that he could enliven his pages with a multitude of anecdotes and personal details. Green was known only to a small circle of friends, having written nothing under his own signature except one or two papers in magazines or in the Transactions of archæological societies; and the plan of his book, which dealt, in eight hundred and twenty pages, with the whole fourteen centuries of English national life, obliged him to handle facts in the mass, and touch lightly and briefly on personal traits. A summary is of all kinds of writing that which it is hardest to make interesting, because one must speak in general terms, one must pack facts tightly together, one must be content to give those facts without the delicacies of light and shade, or the subtler tints of colour. Yet such was his skill, both literary and historical, that his outlines gave more pleasure and instruction than other people's finished pictures.