What challenges affected the restitution of art during the restitution gap years of 1933-1946?

The restitution of art during the years from 1933 to 1946 faced significant challenges primarily due to gaps in ownership history. This period, coinciding with the rise of Nazi Germany and the subsequent devastation of World War II, resulted in widespread looting and illegal acquisition of artworks. Consequently, many artworks changed hands under dubious circumstances, and the documentation often lacked clarity.

The absence of reliable provenance made it difficult for rightful owners and their heirs to reclaim pieces that had been taken from them. Many artworks were stolen or sold under coercion, and the lack of comprehensive records contributed to confusion about rightful ownership. Determining the original owners and the legitimacy of current possessors became a complex task of uncovering fragmented histories behind each piece. Hence, the significant challenge stems from this inadequate documentation of ownership that persisted throughout those years, complicating the restitution process.