  The inward bound path of discovery unravelling the mysteries of matter and
the forces that hold it together has culminated at the end of the twentieth
century,in a theory of the Fundamental Forces of Nature based on Nonabelian
Gauge Fields, called the Standard Model of High Energy Physics. In this article
we trace the historical development of the ideas and the experimental
discoveries on which this theory is based. This involves the following
components: quantum field theory and quantum electrodynamics, weak interactions
and parity violation, strong interactions and quarks, nonabelian gauge fields
and spontaneous symmetry breaking. We develop these different strands of
history and weave them together. We also mark significant Indian contributions
wherever possible. Finally we have a glimpse at future developments, in
particular quantum gravity and string theory. An Appendix on more Indian
contributions is added at the end.
