For my part, I gave up the prospect of a similar trajectory with only nominal reluctance; I was not as clever as Freddie nor as disciplined, even though my love of reading was as great as his and my gift for language greater. But part of me had always hankered after something more, although I had never been able to decide what that was. I spent a few months in an architect's office, but found it uncongenial, although drawing delighted me then as it still does. I next moved to work in one of the great finance houses in the City, but discovered that while the strategy of high finance had its interest, the daily grind of counting money drove me to distraction. I might have made a splendid Baring, but as one of that family's clerks I was sorely tried.

Still, I did this for several years and gained greatly by the experience – I spent a whole year in Paris, much time in Berlin and even, on one occasion, was sent for two months to New York. At no stage did it occur to me that I was receiving remarkable treatment for a young man with no connections, unproven ability and minimal experience. I realised that most people of my sort spent their time, six days a week, in a dreary office from eight in the morning until seven at night, but I assumed it was merely good fortune on my part that I was not one of them. I was picked for one job and acquitted myself well, and so was chosen for another. And so on. The idea that any other factor was involved did not come into my thoughts.

In July 1887, though, I received a letter from a Mr Henry Wilkinson. This was shortly after my twenty-fourth birthday. A grand man indeed, Deputy Undersecretary at the Foreign Office, a post he had occupied for some twenty years. He was not much known outside the minuscule world of diplomacy, and the name meant nothing to me, but I knew that the invitation to lunch could not be ignored. And when I requested permission from my chief to absent myself, it was given very speedily. No one seemed curious about what it was all about. Which was not really surprising, as they knew perfectly well already.

I went the following Wednesday to the Athenaeum, and met the man who was to be in effect my employer until he died, still in harness, six months ago. Many people have the idea that civil servants are sleek, well-groomed and well-bred people, suave in manner and given to murmuring incisively instead of indulging in ordinary speech like the majority of the population. Such people exist, but the Diplomatic Service in those days still found a place for the eccentric, the unusual and – in at least two cases I have met – the certifiably insane.

Henry Wilkinson did not look like a senior civil servant. He was dressed in a tweed jacket, for a start, which violated all codes of conduct for his class, his employment and his club, which would have denied entry to most members who dared commit such sacrilege. He was much given to grunting and loud exclamations. His emotions, far from being closely controlled and disciplined, overflowed all over the room, and his conversation was filled with loud laughs, groans, chuckles and sighs. He fidgeted incessantly, so much so that I came to dread sharing a meal with him, because his hands were always picking up the salt cellar and banging it on the table, or twiddling his fork around while he was listening. Or he would cross his legs, uncross them and cross them again, leaning back and forward in his chair as he spoke. He never sat still, never relaxed, even when apparently enjoying himself. He also ate virtually nothing; a meal consisted of chasing a piece of meat around the plate for a few minutes before he consented with the greatest reluctance to push a sliver of carrot or a fragment of potato into his mouth. Then, a few moments later, he would thrust the plate aside as if to say – thank heavens that's over!

He was a wiry man, with a thin, foxy face redeemed only by a most charming smile. He also had the annoying habit of almost never looking directly at you; this he kept for special occasions, and when he did, his eyes bored straight through you as though he could count the dots on the wallpaper through your head. Every now and then during our lunch, some grandee would bow discreetly at him, but he waved them all aside without even looking at them.

It was not so much a lunch, more of a viva voce examination. I was discouraged from asking any questions, and when I did, they were ignored. What was my opinion of Britain's place in the world? Who were our greatest enemies? Who our rivals? What were their advantages and weaknesses? How best to exploit their divisions? How did the health of our great industries relate to the longevity of the Empire? What proper relationship with the Continent should Britain pursue? Did I think we should continue to bolster the Ottoman Empire, or connive at its downfall? My opinion on the continued convertibility of paper specie into gold? The double metal question? The effectiveness of the Bank of England in the late crisis in the American markets? The use of financial power as a proper instrument of diplomacy?

Most of these questions, I was sure, I answered badly. I was no diplomat, reading secret briefing papers from ambassadors around the globe; most of what I knew was to be found in The Times every morning. Perhaps I was a little better informed on financial matters, but, as I had been pummelled by questions for a long time without making any apparent impression on him, I was beginning to be discouraged, which no doubt made my answers less satisfactory.

'You are asked by your Government to commit a crime, Mr Cort. Do you do it or not? What factors determine your answer?'

This question came out of the blue after a response on my part to a question about whether I considered dividends of North American railway stock to be sustainable (an easy one, that: of course they weren't) and it took me so completely by surprise I hardly knew what to answer.

'It would depend on my position in relation to the Government,' I said after a while. 'A soldier invading a foreign country I suppose commits a crime, but is not held personally accountable. An individual with no official status might be in a less comfortable position.'

'Assume you are a private individual.'

'Then it depends on who is asking this of me. I assume it is a crime for the good of the country. I would have to have a very profound trust in the judgement of the person making the request. Why do you ask such a question?'

This was my second attempt, by that stage, to discover the purpose of the meeting. It was brushed aside, as the first had been.

'Your duty to your country is a matter of personal relations?' he asked, arching his eyebrows in something I took to be scorn. I was becoming a little annoyed by this stage, having endured these incessant questions for more than an hour, so that my plate lay almost as untouched as his; I thought I had been remarkably patient.

'Yes,' I snapped back. 'We are not talking about the country. We are talking about its representatives, only some of whom have the authority or stature to decide what is in the national good. Also I speak as one of Her Majesty's subjects, who has a right to have an opinion on such matters. Besides, I was not aware that our Government committed crimes.'

I glared; he now smiled sweetly back, as though I had just said how pretty his little daughter was. (I met his family once, some years later. His daughter, slightly older than I, was the most terrifying female I ever encountered: the brains of the father, multiplied by the remarkable force of character of the mother. She was not, however, particularly pretty.)

'Goodness gracious me!' he said. 'I don't believe you just said that! Of course it does. Not unless they can be avoided, of course. Let me give you an example. Suppose we learn that France, our great, civilised but entirely annoying neighbour, has advanced plans for an invasion of this country. Suppose we know how to obtain these plans. Should we do so?'