Among the later Byzantine historians the names of John Zonaras, of Nicetas Acominatus, of Nicephorus Gregoras, occur as depicters of the events of somewhat comprehensive periods; Agathias, Simocatta, Epiphaneia, Anna Comnena, and George Phrantzes as biographers or writers on more limited epochs. Of these Anna Comnena in particular is noteworthy because her life of her father Alexius I has been spoken of as the only really artistic historical production of the period. It is popularly known as having supplied Sir Walter Scott with the subject and some of the materials for his last romance, _Count Robert of Paris_. But most noteworthy of all is the fact that this is the first important historical production, so far as is known, that ever came from the pen of a female writer. The list of chronologies or epitomes of world history includes the _Chronicon Paschale_, and the works of Georgius Syncellus, Malalas, Cedrenus, Michael Glycas, and Constantine Manasses. In some respects more important than any of these were the collections of excerpts from ancient authors which were made by Stobæus, by Photius, and by Suidas. These have preserved many fragments of the writings of historians of antiquity that would otherwise have been altogether lost. A very noteworthy collection of excerpts, comprising in the aggregate a comprehensive history of the world made up from the writings of the Greek historians, forms one portion of the encyclopædia which the emperor Constantine (VII) Porphyrogenitus--himself a writer of some distinction--caused to be compiled in the tenth century. This work contained extracts, often very extensive, from the writings of most of the Greek classical historians. It was apparently very popular in the Middle Ages, and has been supposed to be responsible for the loss of many of the works from which it made excerpts. Unfortunately, the encyclopædia itself has come down to us only in fragments; but, even so, it gives us excerpts from such writers as Polybius, Dionysius of Halicarnassus, Diodorus, Nicholas of Damascus, Appian, and Dion Cassius, and of numerous Byzantine histories that are not otherwise preserved.