Another production of some importance was an "Essay towards a Geography of the Old Russian World," by Nadeshdin; in which the author attempted with ability and success to trace the old seats of the Slavic nations. Several monographs and histories of particular regions or periods appeared in the interval between 1830 and 1842. Such were the histories, e.g. of the unfortunate Prince Ivan and his relatives, by Polenof; of Catharine II. by Lefort; of Tzar Boris Godunof, by Krayefski; of Peter II, by Arsenief. Also a History of the time of troubles (as the period between Boris Godunof and the reign of the house of Romanof is called) by Buturlin; the biographies of the first three Tzars of the house of Romanof, by Berg; the histories of Kief by Samailof, of Pskow by Pogodin, of Siberia by Slowzof; of the fair of Nishni Novogorod, which goes back to the fourteenth century, by Zubof; of the Zaporoguean Kozaks by Sreznefski. This latter valuable work is especially rich in historical popular songs, never before printed. Further, the History of the insurrection of Pugatschef, by the poet Pushkin; the Historical and statistical survey of Russia, by T. Bulgarin; and the Memoirs for Russian History by Svinyin (ob. 1839); must be here mentioned. The two latter had hitherto been more known as writers of novels than as historians; and the rosy light which the first of the two tries to throw over his subject, seems still to testify more to his talent for romance than to his historical truthfulness. This was however the spirit in which the government wished its historians to write. A work of decided importance appeared in 1839, a History of Russia, in which the principles of _Panslavism_ were developed in a striking manner. The author, Professor Oustrialof, who had made himself favourably known by several monographs relating to Russian History, has displayed in the above-mentioned work not only considerable acuteness, but also a great deal of research, consistency, and thoroughness.[43] His principal tendency is to represent Russia as the natural central point of the Slavic race. The immediate result of the appearance of this work was, that Oustrialof was commissioned by the government to write a compendium or guide for historical instruction in all the schools of the empire. Although this view may be called the most popular in Russia, it appears from the decided predilection with which Russian writers of history devote their pens to subjects anterior to the reign of Peter I, that they consider the comparatively greater liberty which is allowed them in their researches into the history of this earlier period as a decided advantage. Karamzin had proved by the picture he drew of Ivan the Terrible, that, at this remote period at least, justice was free. It may thus be explained, why Boris Godunof, the friend of the people, the promoter of liberal ideas and modern improvements, is a favourite subject of the young historical school.