The most marked result of these natural conditions has been the isolation, not only of Spain from the rest of the world, but also of the different regions of Spain from one another. Spaniards have therefore developed the conservative clinging to their own institutions and the individuality of an island people. While this has retarded their development into a nation, it has held secure the advances made and has vitalized Spanish civilization. For centuries the most isolated parts were also the most backward, this being especially true of Castile, whereas the more inviting and more easily invaded south and east coasts were the most susceptible to foreign influence and the most advanced intellectually as well as economically. When at length the centre accepted the civilization of the east and south, and by reason of its virility was able to dominate them, it imposed its law, its customs, and its conservatism upon them, and reached across the seas to the Americas, where a handful of men were able to leave an imperishable legacy of Spanish civilization to a great part of two continents. [Sidenote: Events traceable to geographic conditions.] Specific facts in Spanish history can also be traced very largely to the effects of geography. The mineral wealth of the peninsula has attracted foreign peoples throughout recorded history, and the fertility of the south and east has also been a potent inducement to an invasion, whether of armies or of capital. The physical features of the peninsula helped these peoples to preserve their racial characteristics, with the result that Spain presents an unusual variety in traits and customs. The fact that the valley of the Guadalquivir descends to the sea before reaching the eastern line of the Portuguese boundary had an influence in bringing about the independence of Portugal,--for while Castile still had to combat the Moslem states Portugal could turn her energies inward. Nevertheless, one must not think that geography has been the only or even the controlling factor in the life and events of the Iberian Peninsula. Others have been equally or more important,--such as those of race and, especially, the vast group of circumstances involving the relations of men and of states which may be given the collective name of history. CHAPTER II THE EARLY PEOPLES, TO 206 B.C. [Sidenote: Prehistoric Spain.]