The Hanseatic League was one of the biggest trading blocks in middle ages Europe. It also a major political factor in the Baltic. Scandinavian region of Europe it at one point went to war with the kingdom of Denmark. Keen stated that the Hanseatic League was "a federal union of independent towns."1 It went to war rather for economic policy rather then for reasons of foreign policy.
The basic unit of the league was the town or city. As already stated the league was a trade-dominated organisation, its main legislative bodies were called "Diets". The most powerful of these diets being the "general diet"; this was most commonly held in Lubeck. The function of the general diet was to decide the major policies of the league, such as going to war with Denmark over the fish trade. One of the biggest problems of the general diet was that not many of the towns sent delegates to the diet. This was mainly due to the cost, although there might be other reasons, such as a town having to fight off the attempts of its local overlord to gain power over the town. If a town was found to have no real excuse to for not sending a delegate then it could be fined by the Diet.
The next legislative level down was the Regional diet; this was often held more regularly than the General diet. It commonly consisted of several towns who were close to each other. Such as Riga and Livonia. A regional diet might not deal with Hanseatic issues alone; it would also deal with things that effected the towns with in the area of the regional diet. Regional diets were also better attended than the General diets; this was partly due to the issues discussed tended to be more pertinent to the towns that attended and the distance that their delegates had to travel. Both the General diets and the regional diets were also used as courts to resolve trade disputes. The lowest unit was the town council this dealt with issue that effected that town alone, such as domestic issues. One of the biggest problems that league faced in dealing with the town councils, was the Guilds attempts to gain control of the local administrations. The patriarchs in the towns, who were to some degree league sponsored, would often try a limit the power of Guilds attempt to gain power. The position of patriarch was to some degree hereditary.
According to Dollinger, Lubeck was to some existent given limited executive powers to deal with some issues in the time between General diets. With this power had the problem that if the next General diet didn't ratify the acts committed, this could cause a large dispute.
There were other structures and power factors within the Hanseatic League. One of these was being the league's relationship with the Grand Master of the Teutonic order of knights. The Teutonic order dominated a large area of the modern Baltic States and Poland. The Grand Master of the Order was the only independent Prince to sit in the League's diets. It also led to some confusion about the status of his subjects, were they of the Hansa or not.
Another factor that went into the power structure of the Hanseatic League was its division into thirds. These being the Lubeck third, the Westphalian third, and the Saxon third. A principal town controlled these thirds; the principal town was more powerful within the league as a result of this task.
A third factor in the make up of the league was the Kontor. This was a form of trade mission to cities outside the league. It was often contained within a walled enclosure. A Konton was ran by an unpaid leader; it also had it own treasury and a seal. It also had the legal status of a corporation. Pre 1346 the powers of a Kontors were fairly independent, post this date their powers were subordinate to the towns.
As can be seen that League was a highly structured organisation yet it had its problems. One of the major ones was stopping the attempts of local magnates in asserting there power other towns in the area of control. This makes it difficult to work out the real number of towns within the league at anyone time. It should be pointed out that the majority of the Hanseatic League lay within the Holy Roman Empire, and the Lands of the Teutonic order. As a result the actual secular overlords of these lands were often distant or other wise engaged, and this allowed the League to function in the way it did.
Keen M. Medieval Europe (Penguin 1991) P-228