This study attempts to explain how in the twentieth century the concept of a European order which had evolved from the European balance of the nineteenth century, but with an added democratic dimension after 1919 and 1945, played a role in international relations, despite the two world wars which almost put an end to it; how it helped to sustain the concept of a minimum of European solidarity, despite numerous national and ideological conflicts; and how, at the start of a new century, this concept may again be significant for a continent that has not had a similar opportunity to establish a lasting peace since the Congress of Vienna. The concept of a European order may in particular serve as a way of accommodating Russia, which has no real prospect of becoming a member of the European Union.