The Asian lion once occurred in southeast Europe, North Africa, the Middle East, and India. By 1884, it survived only in an area of about 3,000 square kilometres in northern India’s Gir Forest, under the private protection of the ruler of the small state. Official protection by the imperial government was given in 1900, but with increasing human population, overgrazing, and destruction of forest cover, suitable habitat was reduced to about 1,300 square kilometres. In 1957, three African lions, hardly different from their Asiatic relatives, were released in the Gir Forest sanctuary.  Their increase has indicated that such an approach may ensure the continued existence of the lion in Asia. About 85 Asian lions survive in captivity.   

The Asiatic lion (Panthera leo persica) is a genetically distinct subspecies of lion. This genetic difference is small, less than the genetic difference between human racial groups. It is estimated that the Asiatic lion only recently (100,000 years ago) separated from the African population of Panthera leo. Although 100,000 years seems like a very long time; geologically and in terms of evolution, it is extremely short. For this reason, the Asiatic lion and the African lion can still interbreed with each other and have not evolved with reproductive incompatibilities. The biggest visual difference besides size between the two subspecies is a longitudinal skin fold that runs down the belly of persica. This characteristic is always seen in the Asiatic lion and only rarely in the African. Another physical characteristic setting them apart is that the male Asiatic lion has a substantially smaller mane on the top of his head. The mane is sparse enough that the lion's ears are exposed and visible. Its African counterparts' mane is so thick that it obscures its ears completely. Perhaps the most interesting anatomical difference between the two surviving subspecies of lions lies with-in their skulls. The skull of the Asiatic lion possesses two small apertures or holes that allow the passage of nerves and blood vessels to the eyes. The skulls of African lions only have one hole on either side.