Introduction

The restitution of cultural property is an institution of international law that has developed since the nineteenth century [Kowalski, 1998, pp. 8–10]. Initially, it was regulated in peace treaties, under which states were obliged to return specific cultural goods, often exhaustively listed. More detailed regulations appeared after the World War I [van Houtte and others, 2008, pp. 14–16]. Among other things, under the Treaty of Versailles, in relation to Germany, Compensation Commissions were established to examine the amount of damages to be compensated by Germany [Treaty of Peace between the Allied and Associated Powers and Germany, signed at Versailles on 28 June 1919, Journal of Laws – Dz.U. 1920, no. 35, item 200]. The regulations concerning the settlement of settlements between Poland and Russia after the conclusion of the Treaty of Riga of 18 March 1921 were also very developed [ Journals of Laws – Dz.U. 1921, no. 49, item 300]. Pursuant to the provisions of the peace treaty, a Mixed Commission was established in Moscow, which was to decide on the division of the disputed collections, archives. Archives issue was completed on 16 November 1927 with the signing of a general agreement concerning the release or division of archival materials. The last meeting of the Mixed Committee was held on 18 April 1934 and it was not possible to settle all the disputed issues. The world, after the unprecedented scale of bombings that took place during the Spanish Civil War, expected that the next armed conflict would be different from the previous ones and it was necessary to prepare adequate protection of cultural property against their destruction [Nicholas, 2016, pp. 80–81]. The undertaken preparations helped to save only a part of cultural property. The undertaken preparations helped to save only a part of cultural property.

The scale of the looting that took place during World War II cannot be precisely estimated. This issue is extremely complicated due to the fact that it took place both on the Eastern and Western Front. In Western Europe, the Nazis, in order to keep the appearance of acting in accordance with the law, carefully documented the “activities” performed. In the East, all goods were treated as enemy property, products of inferior art, and only the preservation of works of special value was documented [Sichergestellte Kunstwerke im Generalgouvernement].