Born on September 30th, in Warsaw.
(Mother’s name: Cywia Idessa Ejlenberg, father’s name: Hersz Majer Ejlenberg)
Graduated from the Ascola gymnasium (photo) and admitted to the Faculty of Mathematics and Natural Sciences of the University of Warsaw
After completeing studies in Mathematics received from the University of Warsaw with the degree Master' of Philosophy. (Thesis: “On periodic transformations of a sphere”)
Met Garret Birkhoff, Marshall Stone, and Johann von Neumann in Warsaw.
Received Doctoral degree. in Mathematics at the University of Warsaw.
Thesis: “On topological applications of transformations into a circle”.
Advisors: Kazimierz Kuratowski (formal) and Karol Borsuk (de facto).
A visit in Lwów. Six problems included in the Scottish Café book (p. 126, problems 133-138).
Presentation of a paper at the International Congress of Mathematicians in Oslo:
A visit in Cambridge.
Arrived in New York on August 23rd greeted at the harbor by Witold Hurewicz and Henry Wallman
Appointed as an instructor at the University of Michigan, Ann Arbor.
Assistant and Associate Professor, University of Michigan, Ann Arbor.
Met Saunders MacLane in Ann Arbor.
Published the paper ' General Theory of Natural Equivalences' (with MacLane).
Visiting lecturer at Princeton University.
Appointed as a full professor at the University of Indiana.
Took up the post at Columbia University in New York where he remained for the rest of his career.
Met Henri Cartan arriving in New York at the LaGuardia airport.
Became a US citizen.
Year in Paris, on Fulbright Professorship and Guggenheim fellowship.
Became a member of the Bourbaki group.
Published book “Foundations of Algebraic Topology” (with Norman Steenrod).
Published book “Homological Algebra” (with Henri Cartan).
Plenary Lecture at the International Congress of Mathematicians in Edinburgh
“Applications of Homological Algebra in Topology”.
Election to the National Academy of Sciences.
Married Natasa Chterenzon (divorce in1969).
Colloqium lecturer, American Mathematical Society.
Honorary member, London Mathematical Society.
Published “Automata, Languages, and Machines” (volume A & volume B in 1976).
University Professor of Columbia University – retirement.
Doctor Honoris Causa University of Pennsylvania.
Received Wolf Prize in Israel
American Mathematica Society Steele Prize.
Delivered the Wacław Sierpiński Memorial Lecture at the meeting of Warsaw Section of the Polish Mathematical Society “40 Years of Postwar Topology”.
Elected as foreign member of the Polish Academy of Sciences.
Received Honorary Membership of the Polish Mathematical Society
The last visit in Poland at the conferences in Torun and Kazimierz Dolny.
Died in New York on January 30. Obituary in New York Times.