Kate, 35, turned once again to her go-to designer Alexander McQueen, in a chiffon maxi dress currently on sale for £1,453, and a pair of Prada shoes as she arrived at the reception alongside husband William.
The couple are attending the sumptuous party at the British Ambassador's residence in Berlin for a belated celebration of the British monarch's 91st birthday at the end of their action-packed first day in Germany.
The Queen's birthday falls in April but official celebrations take place later on in the summer, and the British Embassy in Berlin mark it each year with a party - even in the monarch's absence.
In a speech tonight, William spoke of his desire for the UK and Germany to remain 'firmest of friends' despite Brexit.
He said: 'This relationship between the United Kingdom and Germany really matters. It is the product of many years of working closely together. It will continue despite Britain's recent decision to leave the European Union. I am confident we shall remain the firmest of friends.'