As the strange floating object moved slowly over highland tribes on its 800 km flight north-west from the Gulf of Papua across English and German and into Dutch New Guinea, the news spread rapidly amongst the isolated people.

On the ridges and in the valleys, people who could only guess at its origin, purpose and intentions nervously watched its progress.

As the airship began its descent, thousands of people crouched in awe.

Two special cameras situated 70 meters apart on the airship filmed the historic event.

The expedition commander, Lt Paul Graetz, a German officer who had famously been the first man to drive across Africa in an automobile, stepped on to the fertile soil of the Wahgi Valley, greeting the astonished onlookers in the name of the Kaiser and becoming the first European they had seen.

But, this alternative history never happened.

World War I intervened and the planned 1914 Deutsch-Englische Luftschiff Expedition that would have changed the history of Papua New Guinea was cancelled.

It was not until 20 years later, in the 1930s, that the Australian Leahy brothers, prospecting for gold, finally make first contact with the isolated highland tribes.

Stamps issued to fund and commemorate the airship expedition - not valid for postage but purchased as collectors' items - are extremely rare and the event that almost but never happened is now a forgotten footnote in PNG's aviation history.

Another of history's 'what if' scenarios.