L. L. Zamenhof (15 December 1859 – 14 April 1917) was an ophthalmologist who lived for most of his life in Warsaw. He is best known as the creator of Esperanto, the most widely used constructed international auxiliary language. In light of his achievements, and his support of intercultural dialogue, UNESCO selected Zamenhof as one of its eminent personalities of 2017, on the 100th anniversary of his death.