Now all these four conditions London enjoyed from a very early time. I have pointed out elsewhere, and shall point out again in these pages, the nature of the political security which London has enjoyed for so many centuries. It did not lie in any particularly peaceful character peculiar to the country as a whole, for while London was growing to greatness England was a continual theatre of domestic war. It lay in the great size which the city had attained, coupled with the breadth of its stream, and in its numerical proportion to the general population of which it was the capital. The fact that London was never besieged or sacked depended upon these characters, and they in turn, therefore, guaranteed that local security which is the first political necessity of a great and continuous market. As to the commercial and productive character of the inhabitants of Britain, it escapes any material analysis. We must postulate it as a constant fact running through the known and recorded centuries of our history, and we may ascribe it according as we more love ease or veracity to whatever cause we feel most flattering or most true. No proof is possible. We can only say in this respect that certain areas of Europe have shown these characters for greater or less periods of time, and that others equally well endowed have not shown them, but have shown other characters perhaps as valuable. The main fact in this connection is that whether the productive areas of Great Britain were exporting raw material (as during the most active centuries of the Middle Ages, when wool was our chief export), or whether (as later became the case) manufactured articles and coal were the stand-by of our oversea trade; whether we consider the period before or after the development of our carrying trade; whether we are concerned with an industrial or an agricultural England; whether we are observing late centuries in which the English showed a passionate interest in novelty and foreign adventure, or far more numerous early centuries in which they were indifferent to distant voyages--throughout the whole story with all its changes the productive area of the island has always maintained a high standard of wealth in comparison with its neighbours and its aptitude for exchange has always been equally high.