President Obama delivered a speech at the Brandenburg Gate on Wednesday afternoon, fifty years after president John F. Kennedy's famous 'Ich bin ein Berliner' address.
The current president used the speech in Berlin to call on Europeans to "lift your eyes beyond the dangers of today" and not retreat inwards.
"When Europe and America lead with hope instead of our fears, we do things no other nations can do," he said.
However the biggest cheer Obama received from the crowd was not when he announced a reduction in nuclear weapons or defended human rights - but when he took off his suit jacket.
Sweltering in the Berlin heat, the president told around 6,000 Germans: "Thank you for this extraordinary warm welcome, in fact it's so warm and I feel so good I'm actually going to take off my jacket. And anybody else who wants to feel free."
The president added: "We can be a little more informal among friends." And the crowd went wild.