  It is a brief review of the physical theories embodying the idea of extra
dimensions, starting from the pre-historic times to the present day. Here we
have classified the developments into three eras, such as Pre-Einstein,
Einstein and Kaluza-Klein. Here the views and flow of thoughts are emphasized
rather rigorous mathematical details. Majour developments in Quantum field
theory and Particle physics are outlined. Some well known higher dimensional
approaches to unification are discussed. This is concluded with some examples
for visualizing extra dimensions and a short discussion on the cosmological
implications and possible existence of the same.
