Thirdly, we must consider the advantage which such sites presented against the attacks of pirates, and the better opportunities for defence which a considerable inland town possessed, with its resources in the surrounding fields and population over the smaller seaports.
In considering the first of these points we must remember that there was always a tendency for the central depôt or main commercial town to arise somewhat inland and to be served by subsidiary ports, if there were no direct access to it by water—and even if there were. Canterbury is an example of this, so is Winchester, so is Amiens, and so is Arras, and so is Caen, and so is Rennes, and a host of others.
In balancing the various advantages offered by various sites for the establishment of a market, a preponderating advantage must always be a position lying in the midst of several centres of production, and, since man is a land animal, these sites would normally lie inland. When they were served by a river so much the better; when they were served by a great and secure river, they could not fail to grow as London has grown.
As part of this ease of access must be reckoned, the peculiar character of the Thames, much more open to the wind than the Seine, not blocked by any island, affording once within the estuary a constant depth amply sufficient for all vessels until quite recent times.
But all this would not have given London its place had not a city established at the lowest crossing of the Thames exercised in a peculiar degree that “draining power” of which I have spoken.
We have seen how the system of British roads necessarily converged upon London, and if we consider one or two other features in English topography, we shall see why London provides a common depôt for nearly the whole of English exports in a fashion which no other city could show for any other equally large area of production.
Before the north of England was industrialised, three things were mainly required to establish what I have called the “draining” power of any market in the island. First, that it should be fairly central to all the south and Midlands; secondly, that it should afford a convenient centre of demand for various foreign products; thirdly, that it should be as close as possible to such continental markets as principally received our export.
Given those three conditions combined in any one place, and so far as the great mass of Britain was concerned, a point would be established to which would flow the main part of the produce which the Continent desired to purchase by exchange.
Observe how all these three conditions coincide in the case of London and of that Lower Thames which was its port.
When I say with regard to the first condition that the point we are seeking must be “central” to the south and east of the Island and to the Midlands, I am using a word which needs expansion. I mean that we must have a point to which the communications of commerce already lead, and one not too ex-centric to the area tapped.