In 1887, Ludvik Zamenhof published the "Unua Libro" (“First Book”), the name given to the first four printed pamphlets in Esperanto history. The four similar pamphlets which comprised that “First Book” were written in Russian, Polish, French and German, and served as the model for many other booklets in other languages. Like those first pamphlets, those booklets also contain a justification of the Esperanto project and provide the first elements for its learning (a grammar, a basic vocabulary). The rapid publication of all these documents between 1887 and 1892 is easily explained: there was much at stake. In order for the project to have a chance, the first people who committed themselves to Esperanto had to provide arguments and pedagogical tools popularizing the « international language » as quickly and in as many languages as possible.

The scholars who have as of yet studied the beginnings of Esperanto (Kanzi, Schor, Korzhenkov, in particular) provide more or less complete lists of these pamphlets, manuals and dictionaries, and generally assimilate them to the “First Book” of 1887, but they do not offer further analysis. These scholars have offered an historiography which has focused on the biography of the founder Zamenhof and on the progressive development of the Esperanto movement on a worldwide scale. However, they hardly focus on the authors of these early "propaganda" texts, despite the fact that their activity testifies to the rapid spread of the idea in very different places, cultures and environments.

In the space of a few years, seventeen pamphlets or dictionaries directly derived from the « First Book » were published in the Russian Empire, the German Empire, the United States, Italy, Bulgaria, and other countries. These pamphlets were the work of fifteen authors. Some of them became well-known figures in Esperanto history, such as Lorenz, Bogdanov, Libeks and Geoghegan. Others, however, are basically known only by name (Steinhaus, Marignoni, Nielsen, Najmanovich, Frollo), although their work made it possible to propose the new language to speakers of over a dozen additional languages.

We will present the contents of approximately twenty documents, some of which widely differ from the four originals of Zamenhof, and outline the biographical trajectories of their authors. We will also discuss the remarkable popularity of the first dictionary of 900 words, the initial "vortaro" of Zamenhof, which was reproduced in most of the documents, looking particularly at most interesting adaptation: the esperanto-yiddish dictionary of 1888.