Germany marks 70 years Sunday since the end of the Soviet blockade that sparked the Berlin Airlift, the spectacular humanitarian rescue mission in the early years of the Cold War.
For almost a year, mainly American and British pilots created a lifeline to support war-ravaged West Berlin, then encircled and blockaded by Soviet forces, with food and fuel.
The unprecedented logistical effort with hundreds of thousands of flights to save the city from starvation cemented the post-war German-American friendship.
Here are three things to know about one of the greatest feats in aviation history.
Blockade of a shattered city
After Nazi Germany's defeat, tensions between the West and the Soviet Union resurfaced to divide most of the world into two rival, nuclear-armed camps until the 1989 fall of the Berlin Wall.
In 1945, the four victorious powers, the United States, Britain, France and Russia, split up defeated Germany into four occupation zones, a division mirrored in the capital Berlin.
This left West Berlin, controlled by the Western Allies, stranded like an island deep inside the Soviet sector, which would later become walled-off communist East Germany.
To western powers, West Berlin became a symbolic bulwark of freedom, a sentiment US president John F. Kennedy would later express with the words "Ich bin ein Berliner" (I am a Berliner).
Soviet dictator Joseph Stalin wanted to push western powers out of West Berlin, then a starved city of 2.2 million where entire blocks were reduced to rubble, people were scavenging for food and cigarettes were the black-market currency.
The western Allies instead opted in 1948 to unite their zones into a single economic area with a new Deutschmark currency, paving the way for the creation of West Germany.
In response, Soviet troops on June 24 launched a full blockade of West Berlin. Citing "technical reasons", they closed all roads, railway lines and waterways to the city and shut off electricity.
Spectacular rescue mission
With fears rising that Europe was on the brink of World War III, the western Allies launched an unprecedented rescue effort for the hugely symbolic city.
Starting on June 26, they launched their airlift to fly food and fuel into the besieged city, a mission scaled up soon to see a landing or takeoff in Berlin every 90 seconds.
To break the 322-day blockade, some 277,000 flights brought in more than two million tonnes of food packages and other relief goods.
The planes travelled a combined total of 175 million kilometres, the equivalent of flying around the Earth 4,400 times.
During the operation, Berlin mayor Ernst Reuter made a passionate appeal to the "people of the world", telling them that "you should not, you cannot, abandon this city and this people!"
Berliners fondly remember the buzzing propellers and the so-called "Candy Bombers", those pilots who dropped packages of sweet treats including chocolate, raisins and gum attached to parachutes made out of handkerchiefs.
The first airman to do so was US pilot Gail Halvorsen, now aged 98, whose signature aircraft tilt earned him the nickname "Uncle Wiggly Wings".
The Soviets finally lifted the blockade on May 12, 1949, though the flights continued for several more months.
The daring airlift claimed at least 78 lives, mostly of US and British pilots.
Airport to urban playground
West Berlin used several airstrips, and a river for water-planes, but the main air hub was Tempelhof, the giant terminal of which had been designed fit for the Nazis' "thousand-year Reich".
It closed in 2008, replaced by two other airports, and two years later was declared a vast city park, with skaters and joggers speeding down its disused runways.
Berliners voted to keep it that way, rejecting city development plans in a 2014 referendum.
After Germany's mass migrant influx, its buildings housed refugees from other wars, in Syria, Iraq and Afghanistan.
Today families fly kites where the planes once thundered through the sky, hipster gardeners grow organic vegetables, and a memorial honours the pilots who died to keep West Berlin alive.