The Hanseatic society was a league between several maritime cities of Germany, for the protection of their commerce. Bremen and Amsterdam were the first two that formed it; and the trade of these towns experienced such advantage by their fitting out two men of war in each to convey their ships, that more cities entered into the league. Even kings and princes made treaties with the league, and were often glad of their assistance and protection; by which means they became so powerful both by sea and land, that they raised armies as well as navies, possessed countries in sovereignty, and made peace or war, though always in defence of their trade, as if they had been an united state or commonwealth.

At this time many cities, though they had no great interest in trade, or intercourse with the ocean, entered into this alliance for the preservation of their liberties; so that in 1200 we find no less than seventy-two cities in the list of the towns of the Hanse, particularly Bremen, Amsterdam, Antwerp, Rotterdam, Dort, Bruges, Ostend, Dunkirk, Middleburg, Calais, Rouen, Rochelle, Bordeaux, St Malo, Bayonne, Bilbao, Lisbon, Seville, Cadiz, Carthagena, Barcelona, Marsaclo, Leghorn, Naples, Messina, London, Lubeck, Rostock, Stralsund, Stettin, Wismar, Konigsberg, Dantzig, Elbing, and Marienburg.

The alliance was now so powerful that their ships of war were often hired by other princes to assist them against their enemies. They not only awed, but often defeated, all that opposed their commerce; and in 1358 they took such revenge on the Danish fleet in the Sound, for having interrupted their commerce, that Waldemar III., king of Denmark, for the sake of peace, gave them up Schonen for sixteen years, by which they commanded the passage of the Sound in their own right. In 1428 they made war on Erick, king of Denmark, with two hundred and fifty sail, carrying on board 12,000 men. These so ravaged the coast of Jutland, that the king was glad to make peace with them.

Many privileges were bestowed upon the Hanse Towns by Louis XI., Charles VIII., Louis XII., and Francis I., kings of France, as well as by the emperor Charles V., who had different loans of money from them, and by King Henry III., who also incorporated them into a trading body, in acknowledgment of money which they had advanced to him, as well as for the good services they did him by their naval forces in 1206.

These towns exercised a jurisdiction amongst themselves; and for this purpose they were divided into four colleges or provinces, distinguished by the names of their four principal cities, viz. Lubeck, Cologne, Brunswick, and Dantzig, in which were held their courts of judicature. They had a common stock or treasury at Lubeck, and power to call an assembly as often as was necessary. They kept magazines or warehouses for the sale of their merchandises in London, Bruges, Antwerp, Berg in Norway, Revel in Livonia, and Novgorod in Muscovy, which were exported to most parts of Europe, in English, Dutch, and Flemish bottoms. One of their principal magazines was at London, where a society of German merchants was formed, called the Steelyard Company. To this company great privileges were granted by Edward I.; but these were revoked by act of parliament in 1552, in the reign of Edward VI., upon a complaint of the English merchants that this company had so completely engrossed the cloth trade, that in the preceding year they had exported 50,000 pieces, whilst the English had only shipped 1100 pieces. Queen Mary, who ascended the throne the following year, having resolved to marry Philip, son of the emperor Charles V., suspended the execution of the act for three years; but after that term, whether by reason of some new statute, or in pursuance of that of King Edward, the privileges of the company were no longer regarded, and all efforts of the Hanse Towns to recover this loss were unavailing.

Another accident which contributed to their mortification occurred whilst Queen Elizabeth was at war with the Spaniards. Sir Francis Drake happening to meet sixty ships in the Tagus, loaded with corn belonging to the Hanse Towns, took out all the corn as contraband goods, which they were forbidden to carry by their original patent. The Hanse Towns having complained of this to the diet of the empire, the queen sent an ambassador thither to declare her reasons. The king of Poland likewise interested himself in the affair, because the city of Dantzig was under his protection. At last, though the queen strove hard to preserve the commerce of the English in Germany, the emperor excluded the English company of merchant-adventurers, who had considerable factories at Stade, Emden, Bremen, Hamburg, and Elbing, from all trade in the empire. In short, the Hanse Towns, particularly in Germany, were not only in so flourishing, but in so formidable a state, from the fourteenth to the sixteenth century, that they gave umbrage to all the neighbouring princes, who threatened a strong confederacy against them, and, as the first step towards this, commanded all the cities within their dominion or jurisdiction to withdraw from the union or Hanse, and have no further concern therein. This immediately separated from them all the cities of England, France, and Italy. The Hanse, on the other hand, prudently put themselves under the protection of the empire; and as the cities just mentioned had withdrawn from them, they withdrew from several more, and made a decree amongst themselves, that none should be admitted into their society but such as stood within the limits of the German empire, or were dependent thereon, except Dantzig, which continued a member, though in nowise dependent on the empire. By this means they maintained their confederacy for the protection of trade, without being any more envied by their neighbours; but they were reduced to Lubeck, Bremen, Hamburg, and Dantzig, in the first of which they kept their register, and held assemblies once in three years at least. In the middle of the seventeenth century, Lubeck, Bremen, and Hamburg were all that continued to acknowledge the authority of the league; and even to this day the shadow of its power still exists, these places having been acknowledged in the act for the establishment of the Germanic confederation signed at Vienna on the 8th of June 1815, as free Hanseatic cities.