I meet Greenwood in the master’s lodge at Magdalene College. It is an uninspiring building, with none of the charm of the wider estate. The red statement walls shrouding either side of his study are hideously garish, almost enough to make the Palace of Versailles seem drab. Beyond that, it is a warm space, complete with a generous desk, pair of armchairs, and countless leather-bound volumes of legal literature.

Greenwood is a Magdalene man through and through. He matriculated here in 1973 and was elected to the Fellowship five years later. He married his wife Sue in the college chapel, and his daughters were baptised there a decade later. Discussing Magdalene therefore seemed like a natural place to start our discussion.

What would his contemporaries have thought if they’d been told that one day, 18-year-old Chris would be back as Master? “I should think they would have been astonished. I would have been too!” Greenwood pauses to take a drink, then emits what I can only describe as a healthy guffaw. The idea of being Master is clearly still one he finds ludicrous.

I don’t seem to be in on the joke. Wellingborough, Magdalene, Knight of the Realm, member of the Athenaeum: Cambridge is the only place where a man like Greenwood is as common as muck. The QC is quick to bat away this charge. “If you look at the heads of house, 15 are women, 16 are men, that’s as close to 50-50 as you can get with an odd number. People come from a wide variety of different backgrounds.” As for the Athenaeum, his enthusiasm for the club was somewhat tempered by a meal with a group of ASNACs early in his membership. “Discussing an old-Norse dictionary at dinner certainly strained my powers of small talk!”

Having established that Sir Christopher John Greenwood GBE CMG QC really is just an ordinary guy, what about the students? Magdalene takes close to 67% of undergraduates from the maintained sector, below the university average, and a far cry from Jesus’ 80%. Why is this? “Well, I think that’s a question better asked of the Admissions Tutor. But I can tell you that one of my goals is to broaden the intake of the college. I think we are missing out on some very able students.” Will he commit to matching the university average by the end of his tenure? “No. You have to be very suspicious of quotas.”

“A majority of people felt that independence, national sovereignty and autonomy mattered to them”

We move away from Magdalene and on to his time as a QC. He confirms that he has read his Wikipedia page, but is quick to add he didn’t write it. I believe him. A single event haunts his entry with all the spite of a wicked conscience. The Iraq War. Is the focus on Iraq a fair reflection of his career as a barrister? “I don’t think it’s unfair. People are free to comment on whatever they like.” Greenwood’s turn of phrase changes dramatically, his sentences slower, his choice of words more deliberate. He stresses that he was only asked to “advise about prospective litigation after the decision had been taken.” It was the Attorney General, Lord Goldsmith, “who gave the advice about the legality of force, and he’d written his advice before I was brought it.” The War QC urges me to read the Chilcot Report – an unusually candid suggestion from someone involved in the saga.

Before returning to Magdalene, Greenwood spent nine years as a judge on the International Court of Justice. Is the international justice system fit for purpose? “It’s as fit for purpose as the international community can make it at the moment.” I push Greenwood, highlighting the international community’s inability to curtail Russian behaviour in the Ukraine, or hold Syria’s Assad accountable for his use of chemical weapons. Why doesn’t he think we need some sort of international Leviathan? “I think that would involve such a transformation in international society that would be undesirable”. While accepting that “the nation state model has its disadvantages”, Greenwood points to the Brexit referendum, arguing it showed “a majority of people felt that independence, national sovereignty and autonomy mattered to them.” Is Magdalene’s new master a raging Brexiteer? I know better than to ask.

Almost uninvited, Greenwood begins to wax lyrical about the Law of the Sea. Does he never get bored thinking about who owns a couple of hundred metres of beach? I’ve touched a nerve. His eyes flash with a youthful sincerity, somewhat incongruous in a career QC. Greenwood insists, “Maritime disputes have an elegance and fascination of their own!” I bet he was an absolute hoot in the college bar. His wider point is, however, apt. As an island, we are perhaps oblivious to issues of physical sovereignty. As a colleague once reminded him, “This is the soil of the land that people have fought and died for.”

It has been three years since Greenwood represented Britain on the world stage, but what does he make of our place in the world today? Ever the diplomat, Greenwood says both nothing and everything. Is it okay for Britain to break international law in a specific and limited way? Greenwood offers a resounding “No.” Should ministers who encourage such action consider their positions? “That’s a matter for the minister.” Greenwood’s wry smile offers all the subtext a newspaper journalist could hope for. What would he think of a Foreign Secretary whose blunders exacerbated a British national’s suffering overseas? “He should read his brief better!” The disdain was audible in Basingstoke.

“I wouldn’t accept an appointment on a court where I could be removed at will if the government in question lost confidence in me”

Exceptions aside, Greenwood is unequivocally sympathetic towards the difficult decisions politicians must take. Is it right for the government to allow a representative of Myanmar’s military junta to seize the embassy in London? “I think that’s an extremely difficult question to answer. What you have here is a battle between diplomats from the existing Myanmar delegation. That is a problem that is always exceptionally difficult to deal with. I feel a great deal of sympathy for the Foreign Office about how they cope with this.” Does the public have enough sympathy for politicians? “No – not at all. My experience of government is that they normally bend over backwards to take the right decision.” It would be easy to view Greenwood’s sympathy as yet another example of the ‘good chap’ attitude so common among British governing elites, but he strikes me as sincere. Perhaps he thinks advisers like him deserve some of the same sympathy.

Much has been made recently of retired senior British judges serving on foreign courts, with Dominic Raab suggesting that Lady Hale’s presence in Hong Kong risks offering the Lam regime a ‘veneer of legitimacy’. While professional commitments prevent Greenwood from commenting on Hong Kong, I ask him if he would accept a position on a foreign court where judges serve at the pleasure of the government? “I wouldn’t accept an appointment on a court where I could be removed at will if the government in question lost confidence in me. I don’t think that is an appropriate decision to take. It’s not a position I would accept.” Greenwood’s coded criticism of politicised judiciaries is the first time he strikes me as frustrated by his inability to speak frankly. An eloquent legal mind held hostage by professional privilege and diplomatic duty.

Realising we have spoken for much longer than the 30 minutes we had planned, I ask Greenwood one last question. “Chris, you’ve said nothing in today’s interview that will place you too far up the government’s naughty step. Should we expect to be calling you Lord Greenwood sometime soon?” Once again, Greenwood guffaws. I feel that speaks for itself.