Speaking less than a mile from where President John F Kennedy enraptured Berliners in 1963, he warned of the danger of allowing "new walls to divide us from one another".
"The walls between old allies on either side of the Atlantic cannot stand," he said, emphasising his lines with clipped, precise movements of his hands as his words echoed through the huge crowds.
"The walls between the countries with the most and those with the least cannot stand," he continued, as applause began to ripple amongst his listeners.
"The walls between races and tribes; natives and immigrants; Christian and Muslim and Jew cannot stand," he said.
"These now are the walls we must tear down," he concluded to screams of approval.