1984 World Championship Match envelope, stamp, and cancellation

In 1984, after a decade of supremacy, 33-year-old Anatoly Karpov faced off against 21-year-old Garry Kasparov. This match had no game limit, and the first to score six victories would claim the World Champion title. This epic battle spanned 48 games over five months, becoming the lengthiest world championship match in history and the only one left unfinished.