No book has looked at this long and complicated relationship which was crucial to British politics from 1900 to the 1960s.

Edward VII saw Churchill as a protégé partly, but only partly, because Churchill’s mother was a favourite mistress. Churchill’s relationship with George V was far less warm. George V served in the Navy. Churchill liked to call himself ‘A Former Naval Person’, especially in his telegrams to Roosevelt, but he never served on a ship though he served twice as First Lord of the Admiralty.

The navy was a constant source of friction between George V and Churchill.

From the late 1910s, George V’s eldest son David, who became Edward VIII briefly, was quite friendly to Churchill and even gave him a car when Churchill was a little short of money. George V did not approve of their friendship. Churchill supported Edward VIII in the war of Wallis – Wallis Simpson being the woman Edward insisted on marrying even if it meant having to abdicate. Supporting Edward VIII harmed Churchill politically. George VI did not want Churchill to become Prime Minister in May 1940. He favoured Lord Halifax who was a close friend.

Churchill’s relationship with George VI changed dramatically in the perils of 1940. When Churchill got to 10 Downing Street, they developed first the necessary working relationship and then a close friendship. When Princess Elizabeth succeeded her father in 1952, Churchill saw his role as being that of a mentor as well as her ‘obedient servant’. For her sake, for her father’s sake and for Britain’s sake, he would teach her the intricacies of being a constitutional monarch.

Remarkably not one book has concentrated on the relationships between Monarch and Prime Minister. This book aims to fill that gap.

‘Knowing the great abilities which you possess, I am watching your political career with great interest.’ Edward VII to Winston Churchill

Churchill served five royals – Edward VII, George V, Edward VIII, George VI and Elizabeth II. His wife called him Monarchical Number One. He loved the royals but he knew many of their problems.

He had to deal with many royal crises. Edward VII’s eldest son was involved in a scandal surrounding a male brothel in Cleveland Street, a mile away from Hyde Park. Ten years later, George V had to be grateful to him when, as Home Secretary, Churchill rescued him from the accusation that he was a bigamist. There was logic to his loyalty. Churchill once said, ‘No institution pay such dividends as the monarchy.