On September 22, 1912 Prince Aria Soeria Atmadja, Regent Sumedang (1882 – 1919) at that time made the donated testament letter(wakaf). He donated his own personal things belonging and all things that when he was in charge also the heirloom from the ancestors. The thing that was donated this could be taken by his benefit by the heirs Prince Mekkah. That was indicated by Prince Aria Soeria Atmadja as Nazhir was the officials who replaced his position and were appointed by “ Kanjeng the Government “.
Tumenggung R. Moh Singer, was appointed by the Dutch East Indies government and became Regent Sumedang during 1948 /1949, he saw things donated that came from this Prince Aria Soeria Atmadja was not again to one place and or was arranged/was held by several sides. To control it R. Moh Singer tried to gather again this things and tried to arranged/take care all those things donated by Prince Aria Soeria Atmadja, furthermore was handed over to the heir Prince Aria Soeria Atmadja.
During 1950 the heirs Prince Aria Soeria Atmadja after accepting the thing/the object wakaf this immediately formed Prince's Foundation the Soeria Atmdja Aria (the P.A.S.A Foundation the notary's certificate Mr Soedja no.59 on August 28 1950). To again better in arranging the thing wakaf this was based on the decision of the Sumedang District Court on March 26 1953 N0 29/1953 was formed by the Foundation Prince Sumedang (YPS) with the notary's certificate Mr Tan Eng Kiam no 98 on April 21 1955. Therefore then Nazhir that originally was held by the person of the individual now was carried out by many insiders of a legal body had the shape of the Foundation.
After all the things – the legacy heirloom of the ancestors was gathered then in kept to the Oblique Karena Gendeng building was the place tersimpan him main heirloom objects, then Crazy it was considered “Rumah Pusaka”. To conserve the object – the object wakaf this the Foundation Prince Sumedang (YPS) planned to establish a Museum. Because of plenty of legacy objects that could be made for the aim of the museum activity development efforts of the Foundation's activity that could be useful for wargi Sumedang especially and the Sumedang community generally. Then on November 11 1973 the Waditra Building or this Gamelan Building was declared as the Museum building then stood the Museum of Wargi-Yayasan Prince Sumedang (YPS) that at first was taken off only to in the environment wargi the descendants and a descendants of the Ancestors Prince Sumedang. The Wargi –YPS museum evidently received the response that was good from wargi Sumedang likewise this good response came from the Sumedang community.
In the date 7 – on March 13 1974 in Sumedang was held by the Seminar of Sejarah West Java that was attended by the West Javanese historians. In the good opportunity A Sepuh YPS and A Sepuh Wargi Sumedang proposed to give the name of the YPS Museum that was sent in the forum for the Seminar of Sejarah West Java. And one of the results of the Seminar of this Sejarah West Java could be broken and appointed to give the name of the YPS Museum, was taken from the name of a leading figure who was charismatic that is the King first and last the Sumedanglarang Kingdom that was named “Prabu Geusan Ulun”. Then on March 13 1974 the YPS Museum was given by the name to the Museum of “Prabu Geusan Ulun the Foundation Prince Sumedang.
