The name is a portmanteau of the French words "douze" for twelve and "jumelage" for twinning and stands for the twelve founder members, one for each European Union member state in 1991, when the Douzelage Charter was signed in Granville, France.
Although the membership of the EU, and of the association, has grown, the name Douzelage has been kept unchanged.
The aims of the Douzelage are to promote and foster the spirit of Europe and to establish among others educational, economic, tourist, sporting and cultural links between the towns for the mutual benefit of the inhabitants thereof.
Douzelage is chaired by a president and two vice-presidents, all elected for a period of three years. The official language used is English, partially also French.
The original 12 founding members were:
Towns that joined later are:
In a first step of further expansion, five new towns joined the Douzelage in harmony with the European enlargement process:
Since 2007, eight further towns have joined the organisation:
In 2016 Finland changed its member: