Konrad Jacobs, Erlangen, Copyright by MFO / Original uploader was AEDP at it.wikipedia · CC BY-SA 2.0 de

Reshaped algebraic geometry so thoroughly that his ideas — sheaf theory, scheme theory, a wholesale "relative" way of framing problems — became the field's working language, and he won the Fields Medal in 1966 for it. In 1970, he walked away from the Paris institute where he'd worked for over a decade in protest of its military funding, and later withdrew from mathematics almost entirely, moving to a village in the Pyrenees to live in seclusion pursuing religious and philosophical questions until his death.