In addition to the Yiddish-speaking Jewish majority, the population of Bialystok included Roman Catholic Poles and Eastern Orthodox Russians (mainly government officials), with smaller groups of Belarusians, Germans and other ethnic groups. Zamenhof was saddened and frustrated by the many quarrels among these groups. He supposed that the main reason for the hate and prejudice was in the mutual misunderstanding caused by the lack of a common language. So Zamenhof decided to create a unifying language called Esperanto, which he thought would reduce the time and effort of learning a new language, and foster harmony between people of all different cultures.

Credit: Gabriel Ehrnst GRUNDIN, Public domain, via Wikimedia Commons

Zamenhof spoke 9 languages fluently, so Esperanto was a mix of the languages he spoke, primarily French, English, Spanish, German and Slavic languages (Russian, Polish). These were the main languages of Europe, so it would be easier for Europeans to learn Esperanto. In the late 19th century, Esperanto spread from communities in Eastern Europe and Russia to communities worldwide, like South America, North Africa, Australia and the USA. There were yearly Esperanto conferences bringing its speakers together and discussing the evolution of the language.