Wydział Prawa i Administracji Uniwersytet Warszawski

• born on 21^st April 1914 in Stanislav, Austrian Galicia (now Ivano-Frankivsk, Ukraine)
• 1932-1934: studies diplomacy at the Consular Academy of Vienna
• 1934-1936: studies law at the Law Faculty of the Jagiellonian University
• 1937: earns a doctorate in Law at Jagiellonian University
• 1938-1939: studies at Cambridge University and London School of Economics
• 1946-1947: takes part in the Paris Peace Conference as a member of the Polish delegation
• 1947-1960: director of the Department of treaties and legal jurisdiction in the Polish Ministry of Foreign Affairs
• 1949: earns a habilitation at the University of Warsaw and becomes a senior lecturer there
• 1949, 1951, and 1955: Chair of the Legal Committee of the General Assembly of the UN
• 1952 – 1984: professor at the Law and Administration Faculty, University of Warsaw
• from 1956: a member of the Codification Commission attached to the Minister of Justice
• 1956-1966: a member of the Advisory Committee to the UN Secretariat
• 1956-1969: head of the Public and Private International Law Department in the Institute of Legal Sciences of the Polish Academy of Sciences
• 1958: earns a PhD in Law from Moscow State University
• 1959: becomes a full professor
• 1959: earns a PhD in Law from the University of Lorraine
• 1962-1967: chair of the Legal Subcommittee of the UN Committee for the Peaceful Uses of Outer Space
• 1963-1967: editor-in-chief of the „Studia Prawnicze” legal journal
• from 1966: vice Chair of the Subcommittee for Succession of States at the UN
• 1966-1967: head of the Council, Polish Institute of International Affairs
• 1964-1980: a member of the Expert Committee for drawing the conciliation procedure in the United Nations Conference on Trade and Development
• 1967 – 1993:  becomes a judge on the International Court of Justice
• 1973-1976:  president of the International Court of Justice
• 1975: wins World Jurists’ Award
• 1976: wins Wateler Peace Prize for his work for international peace
• 1976-1993: vice President of the Curatorium of the Hague Academy of International Law
• 1977-1980: vice Director of the United Nations Institute for Training and Research
• 1980: lectures in public international law at The Hague Academy of International Law
• 1987: wins Special Prize awarded by Encyclopaedia Britannica
• died on 14th January 1993 in The Hague

• 1960-1962: president of the Polish Political Science Association
• from 1963: a member of the Institute of International Public Law and International Relations of Thessaloniki
• from 1965: an honorary member of the International Academy of Astronautics in Paris
• from 1966: a member of the Class of Moral Sciences at Bologna University
• from 1969: a member of the Mexican Academy of International Law
• from 1977: an honorary member of the American Society of International Law in Washington
• from 1980: a member of the Académie des Sciences Morales et Politique Institut Francais
• from 1982: member of the Royal Netherlands Academy of Arts and Sciences
• 1976-1993: Stockholm International Peace Research Institute board member

• 1948: Gold Cross of Merit;
• 1951: Officer's Cross (Order of Polonia Restituta);
• 1954: Commander's Cross (Order of Polonia Restituta);
• 1964: Order of the Banner of Labor;
• 1981: Commander's Cross with Star (Order of Polonia Restituta).

Lachs also received honoris causa doctorates from several universities, among others:

• University of Budapest (1967),
• University of Algiers (1969),
• University of Delhi (1969),
• University of Nice (1972),
• University of Bucharest (1974),
• University of Brussels (1974),
• University of Halifax (1974),
• New York University (1974),
• University of Sofia (1975),
• University of Southampton (1975), 
• Howard University in Washington (1975), 
• Simon Fraser University in Vancouver (1976),
• University of London (1976),
• University of Helsinki (1980),
• University of Silesia (1988).

Lachs also became a member of the Law Faculty Council at the McGill University in Montreal.