Though lacking a picture collection to rival its sister college in Oxford, Trinity, as one might expect, possesses one of the finer holdings among the Cambridge colleges. Unsurprisingly for an institution with such aristocratic origins, it is particularly well-endowed with grand manner – that is, full-length – portraits, of which two of the choicest are currently hanging in the Fitzwilliam. This small show is barely a display, let alone an exhibition; the paintings are set among the Museum’s permanent collection of British portraits, and while this coherence of format is welcome and at times instructive, this is foremost an opportunity to examine both works up-close in a well-lit environment before they return to the halls and walls of Trinity.

Temporarily usurping Handel is an image all too familiar to any British schoolchild – the frontal likeness of the college’s founder Henry VIII, originally conceived by Hans Holbein the Younger (1497/8-1543) for a dynastic mural destroyed in the 1698 Whitehall fire. But it is the descendant of Holbein’s painting, Hans Eworth’s (1520-74) portrayal of the notorious Tudor monarch, that hangs on the walls of the Fitzwilliam. Less well known is the likelihood that Henry’s confident stare was an afterthought, since the king is depicted looking rightwards in Holbein’s preparatory cartoon (National Portrait Gallery, London). The more memorable final design readily lent itself to duplication, and the countless replicas it spawned (of which Trinity’s is one) helped render the icon iconic as the king’s portrait circulated through and beyond his realm and life; the college’s version was most likely painted exactly two decades after Henry’s death, and three after Holbein’s original. Regulating the royal image in this way was achieved with the aid of certain reproductive techniques, whose hallmarks are visible here.

Most telling is the schematic underdrawing visible beneath the thinned paint of the face, hands and shoes, executed with a deliberate, hard line betraying the use (as was common) of a pattern traced onto the surface. Because of the practicalities involved, the production of large-scale multiples of the royal image appears to have been delegated to teams of shop assistants, and this assumption is not contradicted here by the formulaic treatment of the face and somewhat muddied colouring of the background, perhaps worsened by over-cleaning. If the presence of Eworth’s monogram situates the panel in his workshop, genre, quality and size complicate the attribution to Eworth himself. While there are several intricate passages, many seem distant from the minute textural descriptions of material which won Eworth popularity with the English elite, and which continue to satisfy in such jewel-like portraits as Lady Dacre with Her Son (National Portrait Gallery). Notwithstanding, this version – with its close cousin at Chatsworth – ranks among the finer variants of Holbein’s design, and is well worth seeing for its scale and majesty.

If Holbein can be said to have initiated the revered tradition of portrait painting in Britain, its apogee in the late eighteenth century is represented here by a slickly painted likeness of the four-year-old William Frederick, later student of Trinity and Duke of Gloucester, by the most celebrated (if contested) British portraitist, Sir Joshua Reynolds (1723-92). Aristocratic child portraits present a specific problem for painters, demanding a judicious balance of spontaneity and decorum that can easily be misjudged. Reynolds succeeds here, and if his characterisation lacks the latent animation vivifying Titian’s greatest portrayals of children, his preference for formality prevents charm turning saccharine (readers familiar with Reynolds’ oeuvre will hopefully concur that a looser thematic display here is preferable to his portrait of Master Crewe).

This restraint, moreover, deliberately recalls the work of the third triumvir who dominates histories of portraiture in Britain alongside Holbein and Reynolds – Sir Anthony van Dyck (1599-1641). Van Dyck’s portraits remained extremely popular for well over a century after his death, and his dignified, often allegorical manner was suggested (or even recommended) by the young Duke of Gloucester’s clothing. His ensemble, finished with a plumed hat, laced collar and sleeves, and boots with ornamental spurs, is only one instance of a vogue for early Stuart fashion so indebted to portraiture that it was often referred to as ‘van Dyck’ clothing.  This was especially popular as fancy dress, and through his appeal to ‘historic art’, Reynolds similarly warms the gravity of his sitter’s pose with a touch of playfulness and theatricality to create a far subtler characterisation than first impressions might suggest.

Such alterations to a display of this kind are not intended to make an overall argument, especially when the thematic affinities are faint. In contrast to the excellent thesis-driven exhibitions we continue to be treated to at the Fitzwilliam, this successful integration into the permanent collection provides a window to enjoy two paintings not to be repeated in the foreseeable future, and picture-lovers in Cambridge this month should not leave without seeing them.

Hans Eworth’s portrait of Henry VIII and Sir Joshua Reynolds’ painting of William Frederick, 2nd Duke of Gloucester, are on loan from Trinity College to the Fitzwilliam Museum in Gallery 3 until Sunday 30th August. Admission is free.