100 years ago a Polish-Jewish doctor, Ludwik Zamenhof died in Warsaw. Although you might not recognise his name, Zamenhof is known as the father of Esperanto, the most popular constructed language in the world.
As a young man living in Bialystok -- which is today north-east Poland but which at the time was part of the Russian Empire -- Zamenhof was dismayed by animosity and prejudice among locals.
He grew up absorbed by the idea of a world without conflict and a language that could facilitate communication between different people.
Filip Warwick reports.
Daily newsletterReceive essential international news every morning
Subscribe