It was the beginning of the end of communist East Germany, the passing of the Iron Curtain into history.
August 1989 - and Hungarian border guards had, for the first time, allowed East Germans to cross freely into Austria, leaving behind them one of the most oppressive of the communist regimes.
Thirty years on, the landmark crossing was remembered in Sopron - the Hungarian town which bore witness to this historic event in European history.
Hungary planned to open its border with Austria symbolically for just three hours.
But a border gate was broken before the official opening, after hundreds gathered in the hope of the chance to flee.
It would then take just three short months for the Berlin Wall to fall.
(SOUNDBITE) (German) GERMAN CHANCELLOR ANGELA MERKEL, SAYING: "The Hungarian border guards did not shoot.
They let the East Germans go.
They showed courage by placing humanity above official instructions.
We Germans remember with great gratitude Hungary's contribution towards overcoming the division of Europe and Hungary's contribution towards German reunification." But the first country to dismantle the east-west frontier, was more recently the first to fortify its southern border against a new influx of immigrants.
Hungary's "fortress Europe" threw a wrench into its usually close ties with Germany.
Three decades on, the message from Berlin was clear: the lessons of history must never be forgotten.
(SOUNDBITE) (German) GERMAN CHANCELLOR ANGELA MERKEL, SAYING: "In light of the big tasks we Europeans face today we should recall the values which unite us in Europe.
We should always remember that national well-being always depends on European common well-being." Germany may not have agreed with Hungary on immigration issues in recent years, but it's role in helping break down the east-west frontier is one it will forever be grateful for.