I first saw the Salvator Mundi on April 27, 2005. A longtime friend, an art historian and dealer in Italian Old Master paintings, brought it to the apartment I shared with my husband, Mario Modestini. He had just received it from a New Orleans auction house and was hoping that I would agree to restore it. As is now well known, the Salvator Mundi was later recognized as a lost work by Leonardo da Vinci, and in 2017 it became the most expensive painting ever sold, bringing in $450.3 million at auction at Christie’s. But it was Mario, in the last months before his death, who first recognized the power of this disquieting portrait of divinity—a persona unseeing, all-knowing, eternal, pitiless, like the universe itself. After all that has happened since that day in April—the sale, the debates over authenticity, the accusations of manipulation—I often wonder what Mario would say about the doubters.

As my husband was, I am a restorer of Old Master paintings. I am good at it and treat my responsibility with the utmost gravity. The restoration of a badly damaged painting, especially when it is by a very great artist, always arouses criticism, not least from oneself. It is, unavoidably, an interpretation, like a musical performance except some of the notes are missing. All you have to go on are the well-preserved areas of original paint. These are sacrosanct.

While restoring the Salvator Mundi—work that I began in April 2005 and finished in September 2010—I made sure that my feeble retouches never masked these precious traces. To match the original paint, I built up the retouches in thin layers in the same sequence used by Leonardo. Fearful of covering any original paint, I used the tiny 000 sable watercolor brushes made by Winsor & Newton. Each brushstroke was carefully judged, based on knowledge of similar works and the formal structure of adjoining passages.

Even so, many of the gadflies who make their living on the fringes of the scholarly art world appear to believe that a restorer—in this instance, me—is capable of creating the Salvator Mundi. I suppose I should be flattered. One well-regarded art historian repeated this absurd notion in her soon-to-be published book on Leonardo. As Mario used to say, “She must be blind.”

The power of this disquieting portrait of divinity—a persona unseeing, all-knowing, eternal, pitiless.

It is now 500 years since the death of Leonardo and fewer than 20 paintings have been attributed to him. Many of them were not documented in his lifetime, and there are numerous copies by his followers. New attributions have always been contested and, understandably, must meet the highest standards. In 2008, after three years of examination, a majority of the National Gallery’s panel of experts accepted the Salvator Mundi, justifying its display in the museum’s 2011–12 exhibition.They responded to the magisterially painted blessing hand; the ringlet curls on the left, identical to those in Saint John the Baptist; the rendering of the hand refracted through the crystal sphere, with its accurately described inclusions; and the many-layered buildup of the flesh tones.

In 2017, the Salvator Mundi, Latin for “Savior of the World,” sold at auction for $450.3 million.

Since the sale, the painting has disappeared from public view and cannot speak for itself, leaving hacks and gossip-mongers to advance any tale or theory they choose. One of these is that the Louvre does not wish to include the painting in its exhibition on Leonardo—opening later this month—because its curators do not accept the attribution. I know with absolute certainty that this is pure fabrication. The reason for the Salvator Mundi’s absence from the Louvre show resides with the painting’s likely new owner, Saudi prince Bader bin Abdullah bin Mohammed bin Farhan al-Saud. (Most recently, the painting was scheduled to be unveiled at the Louvre’s Abu Dhabi outpost, before its display there, too, was postponed indefinitely.)

I cannot deny that my privileged relationship with the Salvator Mundi—in this post-truth era—has been difficult. But after the nonsense has run its course, that trance-like gaze, confined by the dimensions of the panel yet exploding from it, will remain: the most supreme representation of spirituality that has ever been painted. This is what my husband, Mario, saw; what transfixed me; and what I humbly sought to restore. —Dianne Modestini