State monopolies were created out of the products of forests, lakes, marshes, shell-fish beds, and salt pans. Mines also became “treasures of the state.”(27) The history of these states reads like a page torn out of the history of early modern Europe. The struggle was half diplomatic and half military. From the beginning of the Spring and Autumn period (722-481 B.C.) to the end of the Age of Warring States (491-221 B.C.), China was subject to frequent war and unstable peace. The character of war itself changed, from a chivalrous exercise almost ritualistic in nature, to a struggle of unrestricted force. The units of government which were to develop into states, and almost into nations, began as feudal overlordships; traditional hatreds and sentiments were developed; diplomatic and military policies crystallized and became consistent; and activities of a state nature became increasingly prominent. Concurrently, other factors operated to prevent an indefinite continuance of these struggles of proto-national states and to avoid the appearance of a permanent system of armed nations such as that which has appeared in modern Europe. The feudal system of China left a strong ethnical, linguistic and intellectual heritage of unity, which was stronger than the cultural disunities and particularities appearing in certain of the states. (The state of Chêng was particularly conspicuous in developing a peculiar state culture.)(28) As the states became larger and larger with the passing of time, they tended not only to develop certain large differences between themselves, but to eradicate the minute local peculiarities of the old system, and in so doing to increase the general homogeneity which was also a heritage of the past ages. This general homogeneity found a living symbol in the persons of the Chou Emperors who, possessed of no more power than the Tennos under the Shogunate, acted, as did their Japanese analogues two thousand years later, as the quasi-religious personifications of the whole general community. It thus occurred that the old feudal system was destroyed by the growth of a general non-feudal economy and political order, which, in its turn, led to the development of the great imperial system under which China continued for many centuries. The period of the transition, during which the traditional feudal unity had been shaken and the new imperial unity not yet established, was a tumultuous and bloody one. The presence of a confederation under the hegemony of some one state—the so-called Presidency—provided a suitable framework for rivalries toward power, without particularly increasing the general peace.