In which year was Korean peninsula divided into two countries?

The leaders of North and South Korea met this week. It was the first such meeting in seven years, and only the second since Korea was divided in nineteen fifty-three.
    South Korean President Rob Moo-hyun and North Korea’s Kim Jong Ⅱ ended three days of talks in Pyongyang on Thursday. They signed a joint declaration to support peace and economic growth on the Korean peninsula.
     It says the South and the North will closely cooperate to end military hostilities and ease tensions. The two Koreas have been increasingly cooperative, but technically they are still at war.
    The North invaded the South in nineteen fifty. A truce halted military action three years later. But it was never replaced with an official peace treaty.