The Queen and the Duke of Edinburgh sat down to lunch with their German relatives today - and one declared his country did not want Britain to leave the European Union.
Prince Donatus of Hesse, a distant family member of both Philip and the Queen, said his nation had taken Die Queen, as she is known by ordinary people, to heart after thousands lined the streets of Frankfurt to welcome the royal couple.
Philip met three branches of his family - Battenberg, von Baden and Hesse - when he and the Queen enjoyed a lunch in the heart of the city.
Prince Donatus 48, shared a table with the Queen and Germany's president Joachim Gauck, and nearby was seated the Duke with other guests at the Romer - Frankfurt's historic city hall.
Asked about the significance of the monarch's visit to the Bergen-Belsen prisoner of war and concentration camps tomorrow, he replied: "It is very important, this is her fifth visit and it shows the importance of the British-German relationship - everyday it has to be worked on.
"And of course we Germans want to see the British stay in the European Union."
The Queen, who is on a state visit to Germany, last night gave a banquet speech where she spoke of the need for unity in Europe which some have interpreted as the monarch entering the EU debate.
Among the dinner guests were German chancellor Angela Merkel and David Cameron who, in his bid to reform Britain's membership of the European Union, met EU leaders in Brussels today to put his case.
They now look set to give the green light to six months of behind-the-scenes talks on Britain's demands for changes to the terms of its EU membership.
A Buckingham Palace spokesman said: "The Queen's speech speaks for itself on the threats of division and the benefits of unity.
"As ever, the Queen is above politics and is politically neutral on the EU."
Philip has close ties with German nobility as his four sisters married German princes before the Second World War.
Donatus's great uncle Prince Christoph of Hesse, who was married to Philip's sister Princess Sophie, was reportedly an SS officer and Luftwaffe pilot.
Philip's mother was Princess Alice, the eldest child of Prince Louis of Battenberg who became a naturalised British subject in 1868 and during the First World War changed the family name to Mountbatten.
Donatus said after the lunch: "It's great to have the Queen here, you see the citizens of Frankfurt are excited to have them as guests in the city and it shows that the Germans are very interested in the British people and the country."
The prince, who was spotted sharing a joke with the Queen at one point during the meal, said: "We had a good table and I know her of course as a relative and I see her once in a while.
"I was only able to talk to Prince Philip for a second, we weren't on the same table.
"I'm related to both the Queen and Prince Philip, because Prince Philip is a Battenburg.
"Mountbatten is Battenburg and Battenburg is coming from my family and I'm also related to the Queen through Queen Victoria - she's my great, great, great grandmother, something like that.
"Normally I meet the Queen in England at Windsor so it's lovely to see them here."
Whenever he saw the Queen he said was "astonished" at the enthusiasm and excitement she generated in the ordinary people around her.
Commenting on the thousands who had gathered in the old city centre of Frankfurt to catch a glimpse of the Queen he said the monarch was "their Queen".