They shook hands with a double clasp at the bottom of the aircraft steps, and exchanged a few pleasantries, and in doing so ensured that nothing would ever be the same again on the divided Korean peninsula.
Yesterday's meeting in Pyongyang between South Korea's President Kim Dae-jung and North Korea's Mr Kim Jong-il ended a 55-year stand-off between the two heavily-armed adversaries, and held out hope for 70 million Koreans of a thaw in the last major confrontation of the Cold War.
The day exceeded the wildest expectations of the South Koreans. Mr Kim Jong-il, rarely seen in public, turned up at the airport to greet his southern counterpart and laid on an honour guard of goose-stepping soldiers in jackboots and with fixed bayonets and ceremonial swords.
As they strolled along a red carpet greeting dignitaries, women in traditional high-waisted Hanbok dresses cheered hysterically and bobbed up and down with excitement, waving pink-and-red paper azaleas, North Korea's national flower. Even the usually grim-faced cadres smiled.
In another surprise, Mr Kim, in sunglasses and dressed in his trademark khaki tunic, led his dark-suited guest to a black Lincoln Continental, and the two leaders drove together into Pyongyang holding hands and promising to do their best for national reconciliation during their three-day summit meeting.
Up to a million well-drilled people waving red bouquets lined the 25 km route into the North Korean capital chanting "Kim Jong-il", an astonishingly large turnout given that up to Monday the North Korean media had made no mention of the summit.
"June 13th will be a day recorded in history," Mr Kim Jong-il told his guest at the State Guest House known as the "pavilion of 100 flowers".
"Let's get on and make that history," replied Mr Kim Daejung, who said he was overwhelmed by the welcome he had received. "I will try not to be too proud. And you will not be disappointed," the North Korean leader promised.
The first meeting lasted only 27 minutes and the topics were not disclosed but the North Korean leader was heard to say: "Let's dispense with protocol and talk freely."
North and South Korea have formally been in a state of war since the 1950-53 Korean War ended in an armed truce. Aid to impoverished North Korea and separated families are expected to top the agenda.
People in the South Korean capital Seoul, which lies within reach of North Korean artillery, applauded as they watched the handshake on television.
President Kim arrived in Pyongyang at 9.25 a.m. local time after an hour-long journey from Seoul during which his aircraft had to detour around the demilitarised border.
As he emerged from the presidential plane marked Republic of Korea, he paused and gazed into the distance, clearly savouring his first moments in North Korea.
"It was not just once or twice that I plunged into deep despair thinking that I would never be able to step on the soil of the North in my lifetime," President Kim remarked.
Later, in a banquet speech, he said he hoped the summit would be a turning point for seven million separated families, and proposed opening road, rail, sea and air connections as a practical way of easing tensions.
"When that happens, all Koreans will be able to travel freely between the two sides and work towards reconciliation, co-operation and eventual reunification," he said.
"It is my desire that, through this visit, 70 million Koreans will be able to be liberated from the fear of a possible war. "We will not be able to resolve all at once the bitterness that has accumulated over the past half century. But well begun is half done."