This meant, however, that a part of China which for several centuries had been Chinese was given up to the Hsiung-nu. This was not, of course, what Ts'ao Ts'ao had intended; he had given the Hsiung-nu some area of pasturage in Shansi with the idea that they should be controlled and administered by the officials of the surrounding district. His plan had been similar to what the Chinese had often done with success: aliens were admitted into the territory of the empire in a body, but then the influence of the surrounding administrative centres was steadily extended over them, until the immigrants completely lost their own nationality and became Chinese. The nineteen tribes of Hsiung-nu, however, were much too numerous, and after the prolonged struggles in China the provincial administration proved much too weak to be able to carry out the plan. Thus there came into existence here, within China, a small Hsiung-nu realm ruled by several _shan-yü_. This was the second major development, and it became of the utmost importance to the history of the next four centuries. 10 _Literature and Art_ With the development of the new class of the gentry in the Han period, there was an increase in the number of those who were anxious to participate in what had been in the past an exclusively aristocratic possession--education. Thus it is by no mere chance that in this period many encyclopaedias were compiled. Encyclopaedias convey knowledge in an easily grasped and easily found form. The first compilation of this sort dates from the third century B.C. It was the work of Lü Pu wei, the merchant who was prime minister and regent during the minority of Shih Huang-ti. It contains general information concerning ceremonies, customs, historic events, and other things the knowledge of which was part of a general education. Soon afterwards other encyclopaedias appeared, of which the best known is the Book of the Mountains and Seas (_Shan Hai Ching_). This book, arranged according to regions of the world, contains everything known at the time about geography, natural philosophy, and the animal and plant world, and also about popular myths. This tendency to systemization is shown also in the historical works. The famous _Shih Chi_, one of our main sources for Chinese history, is the first historical work of the modern type, that is to say, built up on a definite plan, and it was also the model for all later official historiography. Its author, Ss[)u]-ma Ch'ien (born 135 B.C.), and his father, made use of the material in the state archives and of private documents, old historical and philosophical books, inscriptions, and the results of their own travels. The philosophical and historical books of earlier times (with the exception of those of the nature of chronicles) consisted merely of a few dicta or reports of particular events, but the _Shih Chi_ is a compendium of a mass of source-material. The documents were abbreviated, but the text of the