The number of active members of each country taking part in the Commission is established by Statute. That number changed, almost at the mid-century point of the Commission’s life, in relationship to the density of cities present in the country and to the development of studies in urban history. The number of countries represented in the Commission also changed in that period, above all as a consequence of the geopolical transformation after the fall of the Berlin Wall.
In the early decades, when the dominant language of European culture was French, meetings were conducted exclusively in French. Afterwards, approximately at the beginning of the 80’s, English and German became the principal languages, next to French.
An important reform of the Statute has added honorary members, whose number is unlimited. Honorary members have the same rights as active members, but not the same obligations.
In the 90’s intercontinental members also were added, without voting rights, in the General Assembly. Their broadens the scientific and methodological horizons of the Commission and builds a cultural bridge between Europe and the rest of the planet.