Born in Bralia, Rumania, Iannis Xenakis moved to Greece at the age of ten. His study of engineering was interrupted by an involvement with the Greek resistance effort against the Nazis; during the fighting he lost the use of one eye. Resuming his career after the war, he moved to Paris in 1947 to train as an architect with Le Courbusier, whose assistant he served as from 1948 to 1960.
During this time, Xenakis was receiving tuition from Milhaud and Honegger at the Ecole Normale. His first major composition was Metastasis (1953), and like virtually all subsequent works it drew on his knowledge of mathematics and architectural structure, using algorithmic procedures to incorporate elements one would not normally associate with music. An example of this would be the technique of "Arborescences", which involved drawing plant-like forms on graph paper and transferring the results to pitch notation for string groups. The resulting dense glissandi are typical of Xenakis' style; otherworldly, impersonal but strangely compelling.
His close involvement with the design of the Philips Pavillion at the Brussels World Fair of 1958 led to a meeting with Varèse, whose Poème Electronique was being performed there. Varèse did much to persuade Xenakis of the potential of electronic media, which Xenakis pursued in tape works like Orient-Occident, works for synthesizer and even works composed by computer using random elements and pre-specified rules such as the ST series.
Xenakis incorporated a greater human element into theatrical works such as Medea, which drew on the Greek dramatic heritage. The majority of his pieces have Greek titles, but despite an evident love of his country he was to travel widely, setting up academic departments associated with his interests in France and America.