The Holy Sees Foreign Policies in Inter-War Europe is a collection of essays that offers new viewpoints and interpretations of the pontificates of Benedict XV (1914-1922) and Pius XI (1922-1939). The volume gives an overview of the framework within which the Holy See was navigating while trying to ensure the religious well-being of the faithful all over Europe after the Great War.

The first part of the volume describes how national tensions affected the Vaticans foreign policies and the Catholic Church on local level in Germany, the Free City of Danzig, Eastern Galicia and Malta, while the second part analyses the Holy Sees missionary activities: the visit of Cardinal Willem van Rossum to Finland, the religious situation in Estonia and the Crusade of Prayers for Russia.