For soldiers in the muddy trenches of France and Belgium, the aviators pirouetting high above them might have seemed a race apart, heroic pioneers of a more noble form of combat.
That is until they crashed.
A hundred years ago, on April 21, 1918, perhaps the greatest flyer of them all, the German pilot known as the Red Baron, crashed on Australian-held territory on the Somme with a fatal bullet in his chest.
He was almost certainly shot down by Australian machine gunners but no one can say for sure. Nor can they say for sure if the Red Baron was dead when he landed or died very shortly afterwards.
In a flying career which spanned less than three years, Manfred Albrecht Freiherr Von Richthofen, 25, shot down 80 allied aircraft, making him the top scoring fighter pilot of the Great War.
Von Richtofen was christened the Red Baron because many of his successes were in aircraft painted bright red, initially an Albatross. His final 19 victories were at the controls of a red Fokker Dr.I triplane.
In the century since his death, the Red Baron has become perhaps the pre-eminent Great War figure in popular culture, featuring in books and movies, pop songs and even a cartoon strip.
Yet just who was responsible for his death isn't much clearer now than it was the morning his aircraft came to rest in a field near the village of Vaux-Sur-Somme.
Australian soldiers speedily reached the downed aircraft. But accounts of what unfolded there vary.
"I was the first there with an infantry officer. The Baron was hanging in his harness. We undid the buckle and helped the Baron to the ground," one witness, Bombardier Frank Wormald, wrote in 1981.
"We laid him out. One could see he was shot through the chest."
Wormald attributes no final words to the Baron.
However a number of other Australian soldiers also claimed to be the first to reach the aircraft and have proffered various versions of his last words, generally including the German word 'kaput' (finished).
Von Richtofen had been fatally wounded by a single 303 bullet.
Credit initially was given to Canadian RAF pilot Roy Brown who had fired on the red triplane a short time earlier as it flew low across the Australian lines in pursuit of another allied aircraft.
It's now accepted that the fatal shot, which penetrated the Baron's right armpit, passing diagonally though his chest, could only have come from the ground.
But who fired it?
Wormald has no doubts.
"As I was standing alongside of Buie, I saw his bullets hit the Baron in the chest," he said. That was Gunner Robert Buie, like Wormald a member of the AIF's 53rd Battery.
However there are other contenders.
Both Buie and fellow 53rd Battery Gunner Snowy Evans were firing Lewis guns at the Red Baron at a range of about 250 metres. Some suggest Evans was responsible. Other soldiers were also firing their SMLE rifles at the distant aircraft.
Despite these theories, the person now accepted as most likely to have killed the Red Baron is Sergeant Cedric Popkin, a member of the 24th Machine Gun Company.
Popkin, an experienced gunner, was firing his Vickers machine gun at the triplane at long range as it flew in front of his position immediately before it crashed.
Various scientific analyses indicate the disabling and speedily fatal wound to Von Richtofen was consistent with fire only from Popkin's gun.
In an interview with the Brisbane Courier Mail newspaper in 1964, Popkin, who died in 1968, said he was fairly certain he brought down the Red Baron. But as to pinpointing definitely who was responsible, the controversy would never be resolved, he said.
As for the Red Baron, he was treated as an honoured foe. The nearest allied flying unit, which happened to be the Number 3 Squadron of the Australian Flying Corps, took responsibility for his remains and he was accorded a full military funeral.
Six Australian officers acted as pallbearers and other personnel formed a guard of honour. He was interred at the cemetery at Bertangles near Amiens.
Subsequently, his body was relocated a number of times and now rests in the Richtofen family plot in Wiesbaden, Germany.
And the Baron's famous Fokker?
Wormald said when he first saw the plane it would have been fit to fly away. But that did not last.
"During that day the souvenir hunters of the AIF tore that plane to pieces and when the 3rd Australian squadron picked the plane up that evening, it was a wreck," he said.
Wormald used his pocketknife to cut out the four foot square black German cross on red background from the aircraft's top left wing. This disappeared when he lost his kitbag a short time later.
So, much of the Red Baron's aircraft came back to Australia as small pieces in the luggage of returning soldiers.
Some, such as the aircraft's compass, control column and the Baron's left flying boot, along with pieces of the propeller and red fabric are now in the Australian War Memorial.
Australian Associated Press