[en] Superstrings originated in a 1971 collaboration with Neveu in which a dual string theory that would improve upon the bosonic string theory of Veneziano and others was sought and found. Within the first year, it was shown how one could construct a consistent ghost-free interacting theory of bosonic and fermionic strings. Supersymmetry on the two-dimensional world-sheet was established already in 1971, but it was not until 1976 that the space-time supersymmetry of the theory was understood. In 1972, it was shown that the theory required ten dimensions (nine space and one time) for its consistency. In 1981-82, Green and the author demonstrated finiteness of one-loop diagrams, and in 1984, he showed that the cancellation of anomalies requires that the gauge group be SO(32) or E₈ x E₈