A few years later, Churchill stopped seeing Hunt, having taken offence that when he wanted an appointment at 4.30pm the doctor would not cancel an already-booked appointment. Instead, Churchill became a patient of Sir Charles Wilson, who had trained at St Mary's and had a good First World War, during which he was awarded a Military Cross and wrote his perceptive Anatomy of Courage. Wilson, a fine diagnostician, was appointed a physician at St Mary's, and from 1920 to 1945 was the powerful Dean of its medical school. He was the doctor of Churchill's close friends Brendan Bracken and Lord Beaverbrook, a generous patron of St Mary's hospital and school. I assume, therefore, that Beaverbrook recommended Wilson to Churchill. 

Wilson got the earlier X-rays, did no further tests and we hear little more of Churchill's stomach. When Churchill became Prime Minister in May 1940, the Cabinet ordered that a personal physician accompany him worldwide. Bracken and Beaverbrook recommended the worldly Wilson, by now treasurer of the Royal College of Physicians (and its president from 1941-1950), a supreme wheeler-dealer of medical politics. He commissioned Annigoni for his official portrait, an excellent likeness of "Corkscrew Charlie", as he was nicknamed.

Churchill's first major illness was on 26 December 1941 in Washington, soon after Pearl Harbour, when he pushed open a jammed window and had severe pain in his chest and left arm with breathlessness. This was obviously a coronary episode. Churchill self-diagnosed muscle-strain. Wilson did not tell him the truth, saying merely that his "circulation was sluggish", because he made the rapid decision that neither Churchill nor the British and Americans should know at this most critical time of the war that Churchill was an invalid needing six weeks' bedrest. Wilson told no one. When he prevented Churchill from lifting a heavy box, he was told he was being "heart-minded", so Wilson replied, "You're all right. Forget your damned heart." During the war, Churchill had various episodes of pneumonia, all well managed, including one in London when "two beautiful nurses from St Mary's appeared as if by magic".

Churchill's other dangerous problem was his cerebral circulation. His first stroke was in 1949 and he was told truthfully that it was a temporary impairment of the blood supply to the brain. Wilson, now ennobled as Baron Moran of Manton, and the eminent neurologist Russell Brain, accepted Churchill's insistence on concealment of the truth (except from Beaverbrook). Churchill was determined not to retire, but to continue as leader of the Opposition Conservative Party, and to fight the 1950 election. Yet Churchill had another stroke in January 1950, just before the election in February, which he lost, and a third in May 1950. 

Churchill did win the 1951 election, but by now his intimates found him "past his prime", forgetful and lacking tenacity. After a fourth stroke in 1952, Moran decided to discuss the prognosis with Churchill's Personal Private Secretary, Jock Colville, Lord Salisbury and the Palace. They all agreed that Churchill would refuse the obvious solution to retire to the House of Lords. Churchill recovered but, by March, he had sufficient insight to admit to "a decline in mental and physical vigour". Both Colville and Churchill's wife did not think he would last long as Premier. Yet this insight was countered by self-deceptive wishful thinking that it would be a bad thing for the country if he retired now. Indeed, he told the 1922 Committee of Conservative MPs, "I would not stay if I found I was fading physically or mentally." In April 1953, his heir-apparent, Anthony Eden, had his first operation and Churchill seemed more than happy that he could act as Foreign Secretary, too. 

In June 1953, Churchill had his fifth and most severe stroke, which caused him to stagger and speak with a slur. But the Cabinet noticed nothing amiss. His left side became paralysed and he was driven to Chartwell. He ordered Colville to tell no one. Moran warned that Churchill might die that weekend, so Colville sent for the Chancellor of the Exchequer Rab Butler and Salisbury and told the Palace.