Lazarus Ludovik Zamenhof (1859 - 1917)
pseudonym Doktoro Esperanto
Oculist and philologist, born in Bialystok, Poland. An advocate of an international language to promote world peace, he invented Esperanto ("One who hopes'). The first international Esperanto congress was held in 1905, and although he often spoke at this and later conferences, he would not accept formal leadership of the movement.