The Metal Gear Solid games span across decades, though not in chronological order. This should clear the timeline up.
Metal Gear Solid 5 ended with the revelation that you hadn’t been playing as Big Boss, but as a man who had been brainwashed and surgically altered to think and look like he was Big Boss.
We’ve still managed to scrape together all the information we do have, so here’s everything we know about the Metal Gear Solid 3 remake ... out the origins of Big Boss, a major character ...
Metal Gear Solid 3 radically changed the stealth gameplay the franchise was known for. Naked Snake, later known as Big Boss, has a mission to rescue a Russian weapons scientist from the USSR in 1964.