His father Mark having been a merchant, Alexander Ostrowski attended the Kiev College of Commerce, not a high school, and thus had an insufficient qualification to be admitted to university. However, his talent did not remain undetected: Ostrowski's mentor,
Dmitry Grave, wrote to
Edmund Landau and
Kurt Hensel for help. Subsequently, Ostrowski began to study mathematics at
Marburg University under Hensel's supervision in 1912. During
World War I he was interned, but thanks to the intervention of Hensel, the restrictions on his movements were eased somewhat, and he was allowed to use the university library. After the war ended, Ostrowski moved to
Göttingen where he wrote his doctoral dissertation and was influenced by
David Hilbert,
Felix Klein, and Landau. In 1920, after having obtained his doctorate from the
University of Göttingen, Ostrowski moved to
Hamburg where he worked as
Erich Hecke's assistant and finished his
habilitation in 1922. In 1923, he returned to Göttingen and, in 1928, became Professor of Mathematics at the
University of Basel, until retirement in 1958. In 1950, Ostrowski obtained Swiss citizenship. After retirement, he still published scientific papers until his late eighties. ==Selected publications==