It would be the late Queen Elizabeth II’s final state visit abroad and the trip perfectly encapsulated the monarch’s incredible soft power.

That final state visit was a massively symbolic one, to Germany, taking place shortly after the 70th anniversary of VE Day in June 2015.

This momentous occasion was not lost on Elizabeth who had grown up as a princess during World War Two with German bombs dropping down on London and through her reign had witnessed Britain and Germany become closer and closer economic, political and military partners.

The Queen remarked on these changes during her speech at the State Banquet in Berlin: ‘In the 50 years since our first visit, our countries have lived through many profound changes.

‘I am very glad to record that one of the irreversible changes for the better in my lifetime has been in the relationship between the United Kingdom and Germany.’

Writing in his book which explores the relationship between the monarch and the Prime Minister – titled Power and the Palace – royal author Valentine Low looks back on the Queen’s visit to Germany and reveals how the monarch remains a fascination for the public and world leaders alike.

Low said: ‘Lord McDonald, the former permanent under-secretary at the Foreign Office who was Britain’s ambassador to Germany at the time, recalled how the Queen was driven from the airport to the centre of Berlin in a Bentley with the Royal Standard flying.

‘”As it drove along the urban motorway, the traffic on the other side of the road was stationary, and people were standing on the roof of their cars, waving and cheering as she went by”.

Queen Elizabeth II meets young Germans in Berlin in 2015. This would be the late Queen’s final state visit

The Queen with former German Chancellor Angela Merkel. The final state visit perfectly encapsulated the monarch’s incredible soft power

‘Later, he said the official greeter – the state secretary in the president’s office – told him: “I have never seen anything like that in my life”.’

And it wasn’t just members of the German public who were keen to meet the Queen.

Low said: ‘When the Queen attended a university lecture as part of her engagements, Angela Merkel turned up unannounced to sit next to her.’

The monarch’s presence underpinned the importance of the trip as the state visit came on the run up to the Brexit referendum and to highlight how serious it was the then Prime Minister David Cameron made the usual decision to join the Queen.

Low wrote: ‘Cameron wanted to prepare the ground as well as he could in order to win the sort of concessions he would need to persuade voters to support Remain.’

And the late Queen was crucial to these efforts with the buzz and excitement her visits created.

Sir David Manning – a former ambassador and mentor to Prince William and Prince Harry – speaking to Low said: ‘You are going to get much more public impact from a visit if it is by the sovereign or the heir to the throne, than you are if it is by a British minister.

‘They are not there to negotiate deals. But what you can do is create a climate. And you do get access.’