Early History of Gauge Theories and Kaluza-Klein Theories, with a Glance at Recent Developments

One of the major developments of twentieth century physics has been the gradual recognition that a common feature of the known fundamental interactions is their gauge structure. In this article the authors review the early history of gauge theory, from Einstein's theory of gravitation to the appearance of non-abelian gauge theories in the fifties. The authors also review the early history of dimensional reduction, which played an important role in the developement of gauge-theory. A description is given how, in recent times, the ideas of gauge-theory and dimensional reduction have emerged naturally in the context of string theory and non-commutative geometry.