Solid Snake was created by Hideo Kojima to be the protagonist of Metal Gear in 1987. He has been voiced by Akio Otsuka in the Japanese versions of the games and by David Hayter in the American and European release.
Solid Snake one of three clones of the greatest living soldier; Big Boss. Solid Snake began working for the Foxhound unit of the American Military, his first documented mission was to infiltrate a military base known as Outer Heaven in South Africa. His mission guidelines to find another Foxhound member Gray Fox, shut down Outer Heaven and stop the newly formed weapon Metal Gear. The mission was commanded by Big Boss from a comman station nearby. However upon freeing Grey Fox and moving further into Outer Heaven Snake finds that Big Boss is in fact the leader of Outer Heaven. Snake goes onto to defeat both Big Boss and Metal Gear. However by the time the events of Metal Gear 2: Solid Snake it is shown that Big Boss has survived and along with several other rebels (including Grey Fox) started an uprising in Zanzibar-land. Once again it's up to Snake to sneak in to enemy territory and stop Big Boss and Metal Gear. His mission led him to defeat and "kill" Gray Fox and also "kill" Big Boss. The trauma of these two events and having to "kill his closest friend, rival and tutor (Grey Fox) caused Snake to go into retirement. He moved into a small cottage in the Alaskan mountains and began training sled dogs among other activities. (Metal Gear Solid) Four years later, Roy Campbell and an armed SWAT unit found and coerced Snake into performing "one last mission." Foxhound now led by a new commander have gone rogue and have taken over an Alaskan nuclear dumping grounds (Shadow Moses). Snakes mission; Infiltrate Shadow Moses, rescue Arms-Tech president Kenneth Baker and the DARPA chief Donald Anderson, locate and disarm Metal Gear REX and finally disarm the terrorists/ Foxhound by any means necessary.
Snake's cloned brothers introduced in Metal Gear Solid and Metal Gear Solid 2: Sons Of Liberty, are Liquid Snake, the perfect clone soldier of Big Boss, the leader of the new Foxhound and polar opposite of Solid Snake. Their battle on Shadow Moses ended in the death of Liquid (Until plot related reasons bring him back in Revolver Ocelots arm, see either page for more information) and the epilogue after the credits showed that Liquid in fact had the dominant genes passed down from Big Boss and Solid Snake had the recessive genes. Proving that experience shapes us as a person not our genes or our parents. Solid Snake's other twin Solidus Snake was left out of the tampering and was bred to be a regular heir to Big Boss's name and was left to grow naturally. Solidus and Snake barely had any interaction with each other during the Big Shell incident, Snake's fight lay with Liquid/Ocelot, so Raiden (see his page) fought Solidus with a small amount of assistance from Snake.