Sonia Kovalevsky is the first woman in modern times to receive a doctorate in mathematics. She was born in Moscow in 1850 and moved to Germany in 1868 to study under Karl Weierstrass at the University of Berlin. He privately tutored her because the university did not allow women to attend. She did her most important work in the theory of differential equations, which are invaluable for showing rates of change.

In July of 1874, Kovalevsky was granted a Ph.D. from the University of Gottingen. In 1883, she became a lecturer at the University of Stockholm and was later became the first female math professor. She died of influenza at the age of 41.