Mary Conover Mellon and Paul Mellon went to Zurich in the years before the war to work with Jung, and the foundation they established in 1945 took its name from the village on the upper lake of Zurich where Jung had built, by hand and in stages, the stone tower he retreated to. Mary Mellon, who had driven the project, died in 1946, and Paul Mellon carried it on.
Its instrument was a book series. The Bollingen Series ran to something over two hundred and fifty volumes across roughly a hundred works, published first through Pantheon Books and from the 1960s by Princeton University Press, which continues to keep much of it in print. The foundation also made grants and awarded fellowships, and it wound up its grant making at the end of the 1960s, leaving the series behind it.
It also gave a poetry prize, and that produced the one public controversy in its history. The Bollingen Prize, first awarded in 1949 for a book published the previous year, went to Ezra Pound, then confined in Washington after wartime broadcasts for Fascist Italy. The award was fiercely attacked, the Library of Congress withdrew from administering it, and the prize passed to Yale University, which still awards it.