Wolfgang Ernst Friedrich Pauli was born in Vienna on the 25th April 1900, the son of Wolfgang Joseph Pauli, a medical doctor, and of Bertha Schütz. Pauli was soon intellectually influenced by his father, also a distinguished professor of colloid chemistry and his godfather Ernst Mach, a physicist. Pauli went to the University of Munich in 1918 and studied theoretical physics under Arnold Sommerfeld. According to the University rules, Pauli had to attend a three year course before being admitted to the doctoral examinations. As he already had an excellent command of physics, Sommerfeld entrusted him with writing an article on relativity theory for the Mathematical Encyclopedia. His 200-page article (published in 1921), consisting of the most current work on relativity and some of his own interpretations, was praised by Einstein in public. In 1921 Pauli obtained his doctorate. In the winter term, from 1921 to 1922, Pauli worked as Max Born's assistant at Göttingen University, then he went on to be an assistant of Wilhelm Lenz at Hamburg University. After one year's leave at Niels Bohr's Institute at Copenhagen, in 1924, Pauli's research and interest in the anomalous Zeeman effect culminated in the formulation of the "Exclusion principle" which rules how particles like electrons are distributed in the atom. For this he received the Nobel Prize in 1945. From 1924 to 1928, Pauli was honorary professor at the University of Hamburg. Then, in April 1928, he became Professor at the Eidgenössische Technische Hochschule (ETH) in Zurich. He kept this professorship until his death. In July 1940, Pauli and his wife Franca had to leave Europe because of the war. At the Institute for Advanced Study at Princeton, in New Jersey, he could pursue his work on mesons and cosmic ray physics as a visiting professor. In November 1945, while still at Princeton, he received the news that he had been awarded the Nobel Prize for his "Exclusion principle". It was not until December 1946 that he was able to travel to Stockholm and deliver his Nobel lecture. Pauli obtained American citizenship in January 1946, but he returned to Zürich in the same year to take back his professorship at the ETH. After many years waiting, Pauli became a Swiss citizen on the 15th July 1949. Pauli's theoretical prediction, in 1930, of the existence of the neutrino, was finally borne out by its detection by Clyde Cowan and Fred Reines at Los Alamos in 1956. On the 15th December 1958, at the age of 58, Pauli died of cancer at the Red Cross Hospital in Zürich.