Zamenhof Day Zamenhof Day Zamenhof Day (), also called Esperanto Book Day, is celebrated on 15 December, the birthday of Esperanto creator L. L. Zamenhof. It is the most widely celebrated day in Esperanto culture. On this day, Esperantists hold information sessions and cultural gatherings to promote literature in Esperanto. The history of celebrating Esperanto on Zamenhof's birthday can be traced back to 17 December 1878, when at a birthday party for his 19th birthday he presented to his friends his "Lingwe uniwersala", the first version of his international language. By 1887, this language had evolved into what is now recognized as
Ludwik Hass to his education. He was released in 1948 and remained in the Soviet Union until he returned to Poland in 1957. On his arrival in Warsaw he astounded a welcoming delegation of students, by announcing that he was a revolutionary who wanted to overthrow the bureaucracy. He then sang "The Internationale" and gave a clenched fist salute. 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