Esperanto
L. L. Zamenhof created Esperanto. He grew up in Białystok, a town that was in the Russian Empire,  but is now in Poland. People in Białystok spoke many languages. Zamenhof saw conflicts between individual ethnic groups living there (Russians, Poles, Germans and Jews). He thought that lack of a common language caused these conflicts, so he began creating a language people could share and use internationally. He thought this language should be different from national languages. He wanted it to be culturally neutral and easy-to-learn. He thought people should learn it along with national languages and use Esperanto for communication between people with different native languages.