The Polish Museum, Rapperswil, was founded in Rapperswil, Switzerland, on October 23, 1870, by Polish Count Władysław Broel-Plater, at the urging of Agaton Giller, as "a refuge for [Poland's] historic memorabilia dishonored and plundered in the [occupied Polish] homeland" and for the promotion of Polish interests.
Except for two hiatuses (1927–36, 1952–75), the Museum has existed to the present day—an outpost of Polish culture in Switzerland, a country which, over the past two centuries, has given refuge to generations of Poles.
The Polish Museum is housed in the Rapperswil Castle, atop that town's Herrenberg. Erected in the 12th century by Count Rudolf of Rapperswil, the castle passed, together with the town, into the hands of the Habsburgs. Rapperswil became a free city (Freie Reichsstadt) in 1415, and eventually joined the Swiss Confederation. Over the course of time, the castle fell into disrepair.
In the second half of the 19th century, the castle was leased for 99 years from the local authorities by a post-November 1830 Uprising Polish émigré, Count Władysław Broel-Plater (a relative of Emilia Plater, a heroine of the same 1830 Uprising), who had been in Switzerland since 1844. At his own expense he restored the castle, and on October 23, 1870, opened there the Polish National Museum.
Beginning in 1892, the Museum employed one or more librarians. The second to be hired, who worked there four years (1892–96), was future Polish novelist Stefan Żeromski, who had obtained the post thanks in part to a letter of recommendation from novelist Bolesław Prus. Prus had also stood as witness at Żeromski's 1892 wedding to Oktawia Rodkiewicz.
The Żeromskis and Oktawia's daughter by a previous marriage, Henryka ("Henia"), lived in Rapperswil, in the garret of a three-story house at Bahnhofstrasse 28, owned by a Frau Fäh. When Prus visited them for two months in July–August 1895, Oktawia Żeromska rented a room for him on the building's second floor. Thus, for a time, two of Poland's greatest novelists lived at this one address in Rapperswil, Switzerland.