German mathematician best known for providing the first abstract definition of a field, published in Algebraische Theorie der Korper (1910). This work proved that every field has an algebraically closed extension field. Steinitz completed his doctoral dissertation in 1894, and received an assignment as Privatdozent at the Technische Hochschule Berlin in Charlottenburg. Six years later, he accepted a professorship at the Technical College of Breslau, where he remained for 10 years. He later served as head of the mathematics department at the University of Kiel.