The archives of Rotterdam's Hector Hodler Library and the Universal Esperanto Association were transferred to Poland's National Library during a ceremony in Warsaw on Monday.
Poland's Culture and National Heritage Minister Piotr Gliński said at the ceremony that "thanks to this generous donation," Warsaw's National Library will become "the chief Esperanto documentation centre for researchers from all over the world."
He added that Esperanto was "an important part of Polish and world heritage."
Esperanto was created by ophthalmologist and linguist Ludwik Leyzer Zamenhof, who was born in 1859 and grew up in Białystok, now in eastern Poland.
He spoke Yiddish and Russian at home, learned German, French and Hebrew, and studied the classical languages.
Zamenhof's first Esperanto book came out in Warsaw on July 14, 1887.
Ludwik Zamenhof. Image: Wikimedia Commons/Public domain
The name Esperanto was originally the pseudonym under which Zamenhof published his book Doktor Esperanto, which translates as "he who hopes."
The book contained the 16 cardinal grammatical rules of Esperanto as well as 917 word roots taken mostly from existing European languages: Romance, Germanic and Slavic.
The idea was to create the easiest possible language that could be learned in the shortest possible time.
Click on the audio player above to listen to a report by Radio Poland's Agnieszka Bielawska.