The Normandy landings, made possible by the largest seaborne invasion force ever assembled, were part of the great struggle to defeat Fascism and to overthrow the German, Italian and Japanese Axis.

The task force drew its strength from the great "citizen armies" of Britain, the Commonwealth including Australia, New Zealand and Canada, and America. These troops were putting their lives on the line to win back liberty for the nations already occupied by the Nazis and to defend their own.

They were joined on the ships, in the air, and on the beaches, by thousands more who had even more skin in the game.

These were the free French, the French resistance fighters, the fighting Poles, Czechoslovakians and Norwegians who valued freedom above all else because they knew first hand what it was like to lose it.

Their actions were selfless and they remain heroes all.

Initially delayed by bad weather, the 350,000-person-strong armada finally set sail on the night of June 5.

The first landings, which had been preceded by bombing raids, the dropping of paratroops, and an artillery bombardment, took place at about 6.30am on June 6. Called "the longest day" by the author, Cornelius Ryan, the landings secured most of their objectives but at a heavy cost to both sides.

By the end of the day's fighting an estimated 4414 Allied troops were dead. Another six thousand were wounded, captured or missing.

The war itself, which only came to an end on August 14, 1945, after the use of atomic bombs against Hiroshima and Nagasaki, brought an end to Japan's despotic South East Asian and Pacific tyranny, claimed between 70 and 85 million lives, about three per cent of the global population of 2.3 billion in 1940.

About 40,000 were Australians, up to eight million were German, 500,000 were French, three million were Japanese, 420,000 were American and a staggering 20 million plus were from the Soviet Union.

While, on the one hand, the struggle was inconclusive with many countries such as Poland, Hungary and Czechoslovakia to disappear behind the "Iron Curtain" for decades, it ended the totalitarian menace and set the stage for the rebirth of Germany and Japan as stable democracies.

Of all the many conflicts that made the 20^th century the so-called "century of violence", this is the one over whose justice and legitimacy there is the least doubt.

While the struggle begun by China's pro-democracy protesters 30 years ago, which resulted in the deaths of up to 2500 people, is as yet unresolved the Tiananmen martyrs were on the right side of history.

It is because of their sacrifices, and those of the men and women who fought to free the world from the hegemony of Germany, Italy and Japan, that we need to be on guard against those who would debase our liberties under the guise of protecting them.

More than one commentator has noted it was ironic Scott Morrison had to defend his government against claims it was using the AFP to intimidate the media while attending an event marking the beginning of the battle to set Europe free.