The Kushan Empire originally formed in the 1st century AD in the territories of ancient Bactria on either side of the middle course of the Oxus River or Amu Darya in what is now northern Afghanistan, and southern Tajikistan and Uzbekistan.

During the 1st and early 2nd centuries AD the Kushans expanded rapidly across the northern part of the Indian subcontinent at least as far as Saketa and Sarnath near Varanasi (Benares) where inscriptions have been found dated to the first few years of era of the most famous Kushan ruler, Kanishka which apparently began about 127 AD. The Kushan kings were a branch of the Yuezhi confederation (possibly intermarried with local families) and they had diplomatic contacts with Rome, Persia and Han China. While much philosophy, art, and science was created within its borders, the only textual record we have of the empire's history today comes from inscriptions and accounts in other languages, particularly Chinese. The empire declined from 3rd century and fell to the Sassanid empire and Gupta Empire