It is impossible, in the space available, to tell in any detail the fascinating story of the rise of the Hansa to the position of a great power, with its guild halls and factories in foreign lands, of which the oldest and most important was the Steelyard, in London. The history of this institution is believed to go back to the latter days of the Roman occupation. When the Hanseatic League was at the height of its power--from the last quarter of the fourteenth to the first half of the sixteenth centuries, the Steelyard, in London, closely resembled a state within a larger state. It occupied a site now covered by Cannon Street Station, extending from Thames Street to the river, and bounded to the east and west respectively by All Hallows and Cousins Lane. The Steelyard had something of the appearance of a fortress and was stoutly defended against attack. The community within its precincts was governed with monastic severity. Their affairs were administered by an alderman with the assistance of two adjuncts and nine counsellers who took part in all the State and civic pageants of London as a Corporation. This great German commercial institution on British soil, and the other houses established in other countries, reflected the great power which was wielded by the Hanseatic League in commerce. These German traders, however, realised that their increasing trade on the seas required adequate defence. Mainly at the instigation of the merchants of Lübeck, a considerable navy was created, this German city being dependent for its prosperity mainly upon the herring fishing and curing industries of Europe. In process of time the Germans succeeded in driving away English, French and Spanish rivals, and created a great monopoly of the herring fisheries of northern Europe, from which they drew immense wealth and on which depended a number of other industries. It was mainly for the protection of the Sound herrings that the Hansa undertook against the Scandinavian States the numerous campaigns by which it won the keys of the Baltic. The war which culminated with the peace of Spralsunde in 1370 raised the League to the rank of a first-class sea Power. Encouraged by its success in crushing and humiliating Denmark, the Hansa had little hesitation in measuring itself against England. The towns became associated through the Victualling Brothers with an active form of corsair warfare on English shipping.