Einstein applied directly to the Eidgenössische Polytechnische Schule (later Eidgenössische Technische Hochschule (ETH)) in Zürich, Switzerland. Lacking the requisite Matura certificate, he took an entrance examination, which he failed, although he got exceptional marks in mathematics and physics. The Einsteins sent Albert to Aarau, in northern Switzerland to finish secondary school. While lodging with the family of Professor Jost Winteler, he fell in love with the family’s daughter, Marie. (His sister Maja later married the Winteler son, Paul.) In Aarau, Einstein studied Maxwell’s electromagnetic theory. At age 17, he graduated, and, with his father’s approval, renounced his citizenship in the German Kingdom of Württemberg to avoid military service, and enrolled in 1896 in the mathematics and physics program at the Polytechnic in Zurich. Marie Winteler moved to Olsberg, Switzerland for a teaching post.
In the same year, Einstein’s future wife, Mileva Marić, also entered the Polytechnic to study mathematics and physics, the only woman in the academic cohort. Over the next few years, Einstein and Marić’s friendship developed into romance. In a letter to her, Einstein called Marić “a creature who is my equal and who is as strong and independent as I am.” Einstein graduated in 1900 from the Polytechnic with a diploma in mathematics and physics; Although historians have debated whether Marić influenced Einstein’s work, the majority of academic historians of science agree that she did not.