Over the years Hans Leder developed into a specialist collector of religious and ritual art of Mongolia. Leder estimated his collections at a total of 20 000 items. Leder’s ethnographic collection includes around 4500 objects. The first ethnographica, acquired by Leder in the years 1899 and 1900, are in the Weltmuseum Wien (previously the Museum für Völkerkunde Wien). As the centre of the Habsburg monarchy, Vienna was the centre of Leder’s scientific sphere of activity. As an independent travelling researcher without institutional and financial support, Leder was forced repeatedly and involuntarily to divide his ethnographic collections in order to sell them to museums. These divisions also led to the fact that complete groups of objects are distributed over various museum collections.
Major parts of his collections are in the following museums in Europe: Weltmuseum Wien, Linden-Museum Stuttgart, the Ethnology Museum of the J. & E. von Portheim-Stiftung Heidelberg, the Ethnology Museum at the Leipzig Grassi Museum, the Hamburg Ethnology Museum, the Néprajzi Múzeum, Budapest, and the Náprstek Museum, Prague.
The Hans Leder collection is unique in Europe not just in its extent. It resembles a snapshot of the religious everyday culture in Mongolia around 1900, meticulously collected, with an eye for the inconspicuous, a microcosm which is often overlooked.