The Historians' History of the World, subtitled A Comprehensive Narrative of the Rise and Development as Recorded by over two thousand of the Great Writers of all Ages, is a 25-volume encyclopedia of world history originally published in English near the beginning of the 20th century. It was compiled by Henry Smith Williams, a medical doctor and author of many books on medicine, science, and history, as well as other authorities on history, and published in New York in 1902 by Encyclopædia Britannica and the Outlook Company. It was also published in London printed by Morrison & Gibb Limited, of Edinburgh. A second edition was published in 1907 in London by The Times. Two further volumes were subsequently released in the 5th edition of 1926, titled "These eventful years" and dealing with the First World War, published by Encyclopaedia Britannica.
Others involved were historian Walter Lynwood Fleming, and Rupert Hughes as editor.
Digital reproductions of the volumes are available via the Google Books project (links below). Most have been converted to the DjVu file format and made available on archive.org.
List of volumes
Volume I: Prolegomena, Egypt, Mesopotamia
Google Books link to Volume I
The prolegomena discuss various topics relating to the practice of historical study.
Volume II: Israel, India, Persia, Phoenicia, minor nations of Western Asia
Google Books link to Volume II
Part IV: The History of Israel is based chiefly upon the following authorities, as stated in the front matter: Ernest Babelon, The Holy Bible, T.K. Cheyne, Maximilian Wolfgang Duncker, G.H.A. Ewald, Edward Gibbon, F. Hitzig, J. Jahn, Josephus, Rudolf Kittel, , Max Löhr, L. Ménard, H.H. Milman, D.H. Müller, Salomon Munk, F.W. Newman, E. Renan, A.H. Sayce, George Smith, Bernhard Stade.
Beginning with the Biblical history of Abraham and the early Israelites, Moses, the Judges, Samuel, Saul, David, Nehemiah, it moves on to the Maccabean Revolt, early Christianity, and ends with the Fall of Jerusalem.
Part V: The History of Phoenicia is based chiefly upon the following authorities: A.H.L. Heeren, John Kenrick, , T. Mommsen, F.C. Movers, .
Starting with the origins of the people of Phoenicia, this section documents their rise to maritime supremacy under Hiram I and his successors, Phoenicia under the Persians and Greeks the history of Carthage and its decline with the Punic Wars.
Part VI: The History of Western Asia is stated in the front matter as being based chiefly upon the following authorities: Ernest Babelon, Max Duncker, Paul Karolides, Eduard Meyer, Perrot & Chipiez, Georges Radet, A.H. Sayce, Albert Socin, Charles W. Super.
Quickly detailing the story of the Hittites, it moves on to the Scythians, and Cimmerians, the Lydians and a handful of other peoples of the Ancient Near East.
Part VII: The History of Ancient India gives in its front matter the following authorities from which it is chiefly derived: Arrian, Gustave Le Bon, Eugene Bournouf, Mountstuart Elphinstone, A.H.L. Heeren, W.W. Hunter, Sir William Jones, Ferdinand Justi, Saloman Lefmann, James Mill, Vedas, H.H. Wilson.
In three chapters, a brief overview of the early Hindus, the Vedas, the Brahmins, up to a description of the rise of Buddhism.
Part VIII: The History of Ancient Persia is based chiefly upon the following authorities: Ctesias, A.H.L. Heeren, Herodotus, G.C.C. Maspero, Eduard Meyer, Theodor Nöldeke, H.C. Rawlinson.Beginning with the Achaemenids, this part describes briefly the Medes, Elamites, leading up to the civilization of Persia under Cyrus and Darius I, Xerxes I and Artaxerxes III along with the fall of the empire.