On 18 January 1919 the Paris Peace Conference began, saddled with the task of bringing Europe together again after four years of war.

A few months later, on 28 June 1919, the peace treaty was signed at the palace of Versailles outside Paris. The 440 Articles of the Treaty of Versailles laid down the conditions of the peace agreement between Germany and the victors after World War I.

The Germans had not been able to have much influence on the proceedings. They therefore saw the Treaty as a decree, and signed it under protest. Section 12 of the Treaty contains Articles 109-114, which concern the decisions made about Schleswig.

Article 109 stipulated the two geographical areas where plebiscites were to be held, and laid down that German military personnel and civil servants were to leave the plebiscite areas.

The same Article also stipulated that the plebiscite area as a whole was to be under the jurisdiction of a five-man international commission: three members from the allied countries (England, France and the USA), and one member each from Norway and Sweden.

The commission was named CIS; Commission Internationale de Surveillance du Plébiscite Slesvig. It was invested with general administrative powers, and was to ensure free and unimpeded secret plebiscites in the two zones.

As the Treaty was ratified in the course of the summer and autumn, it became clear that the USA would not ratify it, and that the CIS would thus be reduced to four members.

England and France appointed as members of the Commission their ambassadors in Copenhagen – Sir Charles Marling and M. Paul Claudel respectively. From Norway came Thomas Heyfte, Director of the Telegraph Company, and from Sweden Regional Governor Oscar von Sydow.

The Commission set up its headquarters in the Flensburger Hof hotel on the waterfront in Flensburg. An Englishman, Charles Marling, was appointed chairman and another Englishman, Charles Brudenell Bruce, General Secretary. To provide further assistance, three technical advisers were seconded from Germany and Denmark.

The commission took over the administration when the peace treaty came into force on 10 January 1920. At the same time, English and French troops moved into the plebiscite areas. Their task, supported by a police corps, was to help the commission maintain law and order.

The German currency and tax system was retained, as were the legal system, railways, and the telegraph and postal services. The CIS did, however, issue its own postage stamps.

A joint Danish-German committee for import-export and food supplies helped to ensure that the population had the necessities of life. From the middle of February, a court of law was set up to try cases of assault of a national political character.

The CIS delegated some of its authority to groups of experts manned by both Danes and Germans, and called on Danish and German advisors to solve the sometimes very complicated problems the commission was faced with. This is one reason why we can conclude today that in general the CIS did a very good job.