Tarski was born on January 14, 1901 in Warsaw, then a part of the Russian Empire. His family name at birth was Tajtelbaum, changed to Tarski in 1923. He studied mathematics and philosophy at the University of Warsaw from 1918 to 1924, taking courses with Kotarbiński, Leśniewski, Łukasiewicz, Mazurkiewicz and Sierpiński among others. (See Lvov-Warsaw School.) He got a doctoral degree, under Leśniewski’s supervision, in 1924. From then until 1939 he taught mathematics at a high school and held minor teaching positions at the University of Warsaw. In this period he published prolifically on logic and set theory, building a strong international reputation for himself.  Yet he failed in his attempt to obtain a professorship at the University of Lvov (now Lviv) in 1939. In 1929 he married Maria Witkowska, with whom he soon had two children, Ina and Jan.