Hansa, or the League of Hanseatic Cities, was a confederation grouping many cities and communes, formed to take up common trade ventures on sea and land, protect the merchants' interests, and wage war against pirates and robbers. Hansa's internal organisation was fairly loose, nevertheless it played an important role in shaping international relations, especially in the region of the Baltic and Northern Seas, This was thanks to its own policy, numerous alliances and treaties it signed, the wars it fought, and economic embargoes it imposed. The ultimate authority was rested with the general pan-Hanseatic convention whose resolutions were binding on the member cities. From the very beginning Gdansk was actively engaged in the Hanseatic conventions.
At its peak, Hansa grouped about 70 active member-cities and over 100 minor towns that never played any particular role. The organisation was headed by Lübeck. Its exterritorial offices in Bruges, London, Novgorod, and Bergen played the role of its representations abroad. In its trade operations Hansa did not limit itself to the region of the Baltic and Northern Seas, but reached out as far as Portugal and Spain on the one hand, and Russia, Finland, and Iceland on the other. The emergence of new trade routes ends Hansa's golden age.
| 1256-1264 | The League of Wendish Cities is founded | |
| 1294 | Lübeck is first recognised as the "Hansa Leader" | |
| 1356 | Hansa holds its first Convention | |
| 1557 | The Hanseatic Convention in Lubeck reorganises the union. Four Hanseatic cities, i.e. Cologne, Lubeck, Brunswick, and Gdansk, sign the statute other cities adopt at the Convention. The statute stipulates that any internal disputes between the cities will be settled by a court of arbitration. | |
| 1669 | Gdansk last participates in Hansa's Lubeck Convention |
