Banachiewicz was educated at
University of Warsaw and his thesis was on "reduction constants of the Repsold heliometer". In 1905, after the closure of the University by the Russians, he moved to
Göttingen and in 1906 to the
Pulkovo Observatory. He also worked at the
Engelhardt Observatory at
Kazan University from 1910 to 1915. In 1919, after Poland
regained its independence, Banachiewicz moved to
Kraków, becoming a professor at the
Jagiellonian University and the director of Kraków Observatory (). A major contribution was a modified method of determining parabolic orbits. In 1925, he invented a theory of "
cracovians" – a special kind of matrix algebra – which brought him international recognition. This theory solved several astronomical, geodetic, mechanical and mathematical problems. In 1922 he became a member of
Polish Academy of Arts and Sciences and from 1932 to 1938 was the vice-president of the
International Astronomical Union. He was also the first President of the
Polish Astronomical Society, the vice-president of the Geodetic Committee of The Baltic States and, from 1952 to his death, a member of the
Polish Academy of Sciences. He was also the founder of the journal
Acta Astronomica. He was the recipient of Doctor Honoris Causa titles from the
University of Warsaw (1929), the
University of Poznań (1936) and the
Sofia University in
Bulgaria (1948). The
LU decomposition was introduced by Banachiewicz in 1938. == Honors ==