L. L. Zamenhof L. L. Zamenhof Ludwik Lejzer Zamenhof (; , ; – ), credited as L. L. Zamenhof and sometimes as the pseudonymous Dr. Esperanto, was a Polish-Jewish ophthalmologist and the creator of Esperanto, the most successful constructed language in the world. He grew up fascinated by the idea of a world without war and believed that this could happen with the help of a new international auxiliary language, which he first developed in 1873 while still in school. Zamenhof was born on 15 December (3 December OS) 1859, the son of Markus Zamenhof (27 January 1837 - 29 November 1907) and
Ludwik Hass Ludwik Hass Ludwik Hass (1918–2008) was a Polish historian who specialised in the history of Freemasonry in Poland. Hass was born to Jewish parents in Stanisławow. He was brought up in a middle-class family which had been assimilated to polish nationalism. He attended the University of Lvov, which was then in the territory of the Polish Second Republic. While there he became a Trotskyist. Following the German-Soviet invasion of Poland in 1939 he found himself in the territory of the Soviet Union. He was arrested and sent to Vorkutlag. He attributed his survival due to being assigned office work thanks