Excerpt from The Vanishing Velazquez by Laura Cumming, plus links to reviews, author biography & more

Or rather, in the drowsy shadows of a library in winter, I came upon a curious Victorian pamphlet stitched into a leather-bound miscellany between a quaint history of the Hawaiian Islands and a collection of short stories ominously titled Fact and Fiction. If the owner of this particular volume, a London lawyer with an elaborate Ex Libris plate, hadn't underlined the words "A Brief Description of the Portrait of Prince Charles, afterwards Charles the First, painted at Madrid in 1623 by Velasquez" in heavy ink on the contents page, I might not have noticed it. By such accidents are the traces of people, and pictures, preserved. The pamphlet was anonymous, but someone, presumably the lawyer, had hazarded a name: J. Snare? John Snare? The guess turned out to be right.

John Snare was a bookseller from the market town of Reading in Berkshire. His shop was at 16 Minster Street, the same address as the printer of the pamphlet, which he had evidently written and published himself. Snare describes the portrait quite clearly: it shows the young prince with his large liquid eyes and pale complexion, painted without rigidity or outline in an airy threequarter view. Although the language is occasionally florid—he speaks of manliness and silken locks—for a moment, in the fug of the library at dusk, I seemed to think I had some inkling of this painting, which is commonly mentioned by historians as the one good thing to come out of Charles's visit to Madrid to court the Spanish princess in 1623. In my mind I saw the young Charles, who had entirely failed to charm the disdainful infanta, given a better face by Velázquez, his dignity restored to the point of grace.

Overnight, however, I began to doubt the description so much that I returned the next day to see if I had misread the pamphlet and dreamed fiction into fact. But John Snare and his story turned out to be real.

The pamphlet was in fact a miniature catalogue for a onepicture show held in London to high acclaim in the spring of 1847. But how did Snare come to be its curator, and how did he discover the lost painting in the first place? It wasn't hard to find answers to these obvious questions to begin with; but then the case turned into a deeper mystery.

Snare's feeling for Velázquez touched me. He did not see the painting as a thing apart, remote from his own existence; it filled his mind as if it were a living being. He wrote another pamphlet, and then another, in the hope that others would feel for it, too.

His obsession with discovering a past for the portrait eventually turned him into a detective and sent me on a search of my own. At first I was following the painting, like Snare, but soon I was following the fortunes of the bookseller, too. The trail took me to Edinburgh and a shocking court battle over the picture in 1851.

The trial was a crossfire of rage, persecution and snobbery involving outraged aristocrats and awestruck engravers, experts from Soho and dealers from France, servants who had dusted the picture in an earl's London mansion and frame makers who claimed to have seen it in quite other places. Every class of society was represented, from the Scottish nobility to the typesetters who worked alongside Snare in Reading and remembered his life-ordeath passion for the portrait. I had never encountered a case where the voices of the past were so clearly heard speaking about art in an age before it became densely familiar through museums, exhibitions and reproductions. Scarcely a single witness had seen more than one Velázquez and many testified to the extraordinary surprise of this one, the face of the long-dead prince flashing up into a timeless present.

For the art of Velázquez was rare, unfamiliar, obscure. He left so few paintings—not more than 120 over a forty-year career—it is rightly said that he measured out his genius in thimblefuls.

Excerpted from The Vanishing Velázquez by Laura Cumming. Copyright © 2016 by Laura Cumming. Excerpted by permission of Scribner. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.