1881: Ludwik Witold Rajchman was born in Warsaw Poland.

1900-1907: studied Medicine at Krakow, major in Bacteriology.

1907: learn microbiology in France.

1909-1913: lecturer in the Jagellonian University (Krakow) and then Royal Institute of Public Health (London).

1914-1918: head of the Central Laboratory on dysentery (London).

1921-1939: Director of the League of Nation Health Organization. He extends its scope to include diseases prevention, protection of children and invalids, anti-narcotic efforts rather than just focus on the control of contagious diseases.

1939-1941: Named by General Sikorsky to convince French, British and US Governments to provide food aid to Polish Civilians and Children.

1941-1943: advisor of Bank of China.

1944-1945: Called upon to advise UNRRA (United Nations Relief and Rehabilitation Administration, established in 1943 to bring assistance to war ravaged countries) in health matters.

1946-1950: founded UNICEF and become the first Chairman of this Organization (1946-1950).

1950-1965: co-founded the ICC (International Children Center) in Paris with Debre and become the vice president until he died in 1965.