As explained above, the market for certain commodities are worldwide. Moreover, many of these commodities arc in constant demand, either as basic raw material or as main foods or beverages for a large section of the world's people. England's foreign trade began with the export of raw wool in the thirteenth century, and it was extended by the subsequent development of the chartered companies. These were based in London, and it was there that merchants gathered to buy and sell the produce, which the companies’ ships brought from abroad.
The big change, however, came about with the expansion of International trade following the industrial revolution. The UK became the greatest importing and exporting nation in the world. London, her chief port and commercial city, not only imported the goods which were required for the people of her own country but built up an important business, acting as a go-between in the distribution of such commodities as tea, sugar, hides, skins and wool to many other countries, particularly those of western Europe. Hence formal ‘organized markets' developed. These markets are distinctive in that buying and selling takes place in a recognized building business is governed by agreed rules and conventions, and often only certain persons are allowed to engage in transactions. They are thus a highly developed form of market. Today, London has exchanges or auction centers for such commodities as rubber, wool, tea, coffee, furs, metals (tin, copper, lead and zinc), grain, and shipping freights (the Baltic Exchange). It must not be thought, however, that such organised produce markets exist only in London.