As Maren Heinzerling crossed hands with the most powerful woman in the world, leaned backwards and started to spin her dance partner in a circle, she began to worry.

“What are you doing,” the retired railway engineer recalled thinking. “You are spinning around the room with Angela Merkel.” Heinzerling had to grip the chancellor’s hands tighter as they span faster with each rotation.

“I realised I couldn’t let go, or the chancellor would have careered across the hall and smashed into a wall.”