This article is from the Afghan Hound Breed FAQ, by Janis Nixon with numerous contributions by others.
While the greyhound can take credit for being the oldest sighthound
breed, the Afghan and Saluki are not far behind. In fact it is a
chicken and egg question as to which of the two latter breeds came
first. Unfortunately, any information regarding the Afghan's antiquity
has been lost in the mists of time. Without question, both breeds are
thousands of years old and in the beginning were interbred to produce
the best animal for the climate and terrain to be hunted. The western
world discovered the Afghan during the 19th century when British
soldiers brought the first specimens back with them to England.
Originally there were two types of Afghan: The heavily coated,
close-coupled mountain hound and the lean and elegant desert type,
carrying less coat. Desert and mountain types were interbred,
producing the Afghan we know today.