To commemorate the fiftieth anniversary of the first large exhibition of the works of Mark Rothko in Britain, held in the Whitechapel Gallery in 1961, the same institution has organized a single gallery show. Its focus is just one painting, Rothko’s Light Red over Black of 1957. I have yet to see a mature painting by Rothko that disappoints—though some in museums are insensitively displayed—so it is hardly surprising that this one work should so thoroughly and convincingly command the space it occupies. Viewers are encouraged to recline on beanbags before it, a considerate touch that acknowledges the demands the painting makes of them if they accede to its implicit demand for unhurried concentration of attention. While doing so, they can also listen to recorded commentaries on headphones by a variety of luminaries who recall their experiences of the 1961 exhibition. This might be enough in itself, but there is more.

Curators have the great privilege of access to materials that relate to the artworks in their care. These include correspondence with collectors, scholars, dealers, and sometimes the authors of the works themselves. Traces of business transactions, including dealers’ invoices, can also find their way into curatorial files. Although scholarly researchers can sometimes gain access to this material, it is rarely shown in public. The Tate, thanks to the perspicacity of John Rothenstein, acquired Light Red over Black two years after its completion. The exhibition organizers have persuaded the Tate to show the contents of the files. The result is an extraordinarily informative display.

The correspondence between Rothenstein and Sidney Janis, Rothko’s dealer in New York, reveals the fragile contingency of the conditions of acquisition of Light Red over Black. Janis offered a customary ten percent museum discount, so the Tate paid all of $4,500 for this great work. Was the paint application thin enough so that the canvas might safely be rolled for travel to London? Yes, Janis replied, though—perhaps fortunately—he made arrangements for it to be crated with another stretched painting to be delivered to London. Rothko’s own letter announces his pleasure at the purchase. Then we see the later correspondence in which he offers as a gift to the Tate a group of nine canvases originally intended for the Seagram Building in New York. He had withdrawn from the commission when he (and surely others) realized they were wholly unsuitable for a restaurant. He is to the point, polite, and urbane.

This impression is strikingly reinforced by a group of photographs made during Rothko’s visit to England in 1959. His enthusiastic reception by at least some artists and arts administrators helped inspire the respect and even affection he felt for Britain, which was to prompt the gift of the Seagram paintings in 1968. This is not to claim that Rothko’s generous gift was not without self-interest. His terms were clear. These paintings, which could never be alienated, would ensure him a room to himself, like Picasso and Giacometti, thereby asserting his newly earned status among the already acknowledged great Moderns. It was a brilliant assertion of ambition on Rothko’s part from which the knowing Tate worthies were ready to benefit no less than was the artist.

In the 1959 photographs in Cornwall, Rothko appears with William Scott. In contrast to the earnest, anxious Scott, casual in an polo-necked shirt, Rothko is a gently overbearing presence from another world, every inch the New York sophisticate, polite yet reserved in jacket and fashionably narrow tie. He looks totally though resignedly—even comfortably—out of place against a rough Cornish stonewall. In one photo his young daughter, Kate, clings to him, anxiously eyeing the lens. In another, at a rustic outdoor tea table crowded with pottery plates and mugs, he evokes the shade of the worldly Pieter Breugel visiting the so-called peasants in the sixteenth-century Flemish countryside.

Letters from those who saw him in Cornwall reveal the awe in which some British artists held Rothko, and expose their squabbling and jockeying for his attention. Patrick Heron complains that Peter Lanyon had deliberately kept him from seeing more of Rothko than he could help by not telling Rothko that he, Heron, was living and working in Cornwall (Rothko was understandably oblivious) and had not pointed out his studio to Rothko, even though Lanyon and Rothko had parked immediately in front of it. All this was done, Heron suggests, so that Rothko might think that Heron didn’t particularly want to see him, whereas he was in fact most anxious to spend as much time with the great New York painter as possible.

The Tate’s purchase of Light Red over Black in 1959, Rothko’s Whitechapel show in 1961, and his extraordinary gift of the Seagram Building paintings in 1968, quite overshadow the lionizing and the petty jealousies occasioned by his 1959 trip to Cornwall. However, the letters and photographs from that visit poignantly capture the incommensurability of the two worlds concerned: the emergent giant of Abstract Expressionist New York, and the British reticence of St. Ives, Cornwall, from where—for all the undoubted accomplishments of Scott, Lanyon, Heron, and others—only Barbara Hepworth survives unequivocally in the international canon.

If Light Red over Black is not sufficient to exemplify that chasm, a visit to Tate Modern to view the Seagram Building paintings in the light of Rothko in Britain, can only confirm the scale and scope of Rothko’s achievement. Their dark cold fires assuredly earned Rothko his place in the pantheon, for these are portals to aniconic mysteries; the antechamber to the infinite; afterimages of the blinding sight of omnipotence. Of course two years later he was dead, so the last letters on view at the Whitechapel are of condolence to his widow.

Given what Rothko must have seen in his mind’s eye, it is no wonder that his own expression in the Cornish photos is so abstractedly melancholic. We must thank the Whitechapel and the Tate for opening the files and giving us a glimpse of that great, visionary sadness.