Last week I went to the Royal College of Physicians to take a look at their new display celebrating the Tudor polymath John Dee. I don’t know why but I rather foolishly had no big expectations of the Royal College itself. But what an amazing place! My apathy may have been caused by the fact that their home is in a building designed by London’s number one brutalist concrete maestro, Sir Denys Lasdun. Grade I listed and opened by Her Majesty the Queen in 1964, it’s actually a rather handsome structure and once inside you realise it does a great job. One would expect this incongruous mid-20C building to stick out like a sore thumb amid the classical, cream Nash-ian terrace of Regent’s Park, but no: the RCP’s headquarters is indeed a gracious neighbour.

Provided you sign in and don one of those human cattle badges on a lanyard (yellow), you’re free to explore virtually the whole building unhindered. Most wallspace is covered with portraits of the greats of medicine of the past, by some of the leading portrait painters of their times. Reynolds, Lely, Lawrence, Hoppner, Zoffany. Here and there are portrait busts: I spotted at least one by Roubiliac.

But the most engaging parts are on the ground floor: a large collection comprising several hundred apothecary jars; a museum room with a wonderful, intriguing and sometimes eye-watering collection of historical medical instruments and devices, the pride of which must be the rare example of a 17C Prujean chest, named after Dr Thomas Prujean who devised it; and the Censors’ Room, dressed in the original 16C Spanish oak, transferred from the college’s three previous homes. This is where you would have your final examination to become a Member of the College, that is to say a legally practising doctor of medicine. You’d face the torture of a proper grilling by the leading medical men of their age. Prompted by English physicians of the time, Henry VIII founded the college in 1518 to reflect that which pertained on the continent. Prestige.

What follows about Dee notwithstanding, I’d highly recommend a visit to the Royal College of Physicians any time.

John Dee (1527 – 1608/9), like his exact contemporary Sir Walter Ralegh, was an Elizabethan renaissance man par excellence. The two men had much in common, not least sharing a catastrophic drop from favour when James I became king, despite in both of their cases being friends of – and championed by – young Henry, Prince of Wales. And while Sir Walter may have been a more belligerent man of action, Dee was no mean traveller himself and shared with Ralegh a great the vision of an English Empire.

Dee was a mathematician, an astronomer, a map-maker, an apothecary, a courtier, an achemist. While not a qualified physician, he was sufficiently trusted on medical matters for Queen Elizabeth to send him to Europe to seek a cure for one of her ailments. He believed, as many did then, that we could communicate with angels and indeed less benevolent creatures from beyond the veil. Assisted by his associate, the “scryer” Edward Kelley, he would communicate with spirits. Not surprising, then, that in 1555, Queen Mary had him locked up in the Tower as an alleged sorcerer. Fortunately – and unlike many others – he was able to charm and actually befriend his interrogator, Archbishop Bonner, establish his good Catholic credentials and be given the official stamp of approval.

Like most men of affairs during his era, John Dee was a great bibliophile. His library comprised over 4,000 books and manuscripts, vast by the standards of the day. It was housed at his home, a large house in Mortlake where he also kept his laboratory and entertained guests, including the queen herself. Heartbreakingly for Dee, most of his books were stolen or sold off by an unscrupulous relative – one Nicholas Fromond – while Dee was away on one of his travels. Down the years, over a hundred of these have come into the possession of the RCP, making it the biggest single collection of Dee’s books in the world. A selection of them forms the basis of a new display which opened last week. They are a joy to examine.

Clearly these tomes were not just for display, but for careful reading. For they are heavily annotated by Dee, as was the habit of those times. Underlinings all over the place, and marginalia comprising commentary and the little diagrams of the pointing hand here and there, a common Tudor era device (Henry VIII used it a lot, along with an eye). But there are also other types of diagrams – horoscopes, faces, shapes – particularly where topics like geometry are concerned. Best of all, though, is Dee’s drawing of a ship in full sail in the bottom corner of a page in Cicero’s Opera, published in 1539.

What interested me about this show was thinking about the golden generation of the late 16C – Shakespeare, Dee, Ralegh and their like – and comparing it with another golden generation but very different group a hundred years later – Wren, Hooke, Boyle, Evelyn, Pepys etc. In the interim, Francis Bacon had taught brainy men to think differently and the tumult of civil war and plague had entirely transformed the country, London in particular.

Hence, this exhibition is a must-visit for everyone interested in early modern history: absorbing and thought-provoking.

Scholar, Courtier Magician: the lost library of John Dee runs until 29 July 2016 at the Royal College of Physicians. Entrance is free.