Copper plate etching of Jeremy King brings together ‘two absolute masters of their respective arts’, says Oliver Barker, of Sotheby’s. Photograph: Sotheby's

In subsequent years, the artist frequented the Mayfair restaurant virtually every night and sometimes sat at a table with co-founder Jeremy King

Next month, a Lucian Freud picture of the restaurateur who owns the Wolseley, the Mayfair restaurant where the artist ate almost nightly in the final few years of his life, will be auctioned off.

When Freud passed away in 2011, he was still working on the etching of Jeremy King. After Freud started eating at Le Caprice, another King property (and a favorite of Diana, Princess of Wales), then at the Wolseley when it opened in 2003, the two became close over the course of nearly 30 years.

In the last eight years of his life, Freud frequented the famous art deco restaurant on Piccadilly, which reminded him of the opulent Vienna cafés of his youth.

He often had moules et frites or Atlantic prawns with his own wine that he stored in the restaurant's cellars. He sometimes ate alone himself and other times with other people, such as Kate Moss and David Hockney. King would sometimes join the table even though he often avoided having visitors around for dinner.

Lucian Freud ate at the Wolseley on Piccadilly five or six times a week in the last eight years of his life. Photograph: Sophia Evans/The Observer

The Wolseley covered Freud's corner table with a black tablecloth and lit a solitary candle at the table in his honor the night of his passing.

King, who was also responsible for the Young British Artists' favorite Soho gallery, the Ivy, in the 1990s, sat for Freud twice: first, in 2006–2007 for a painting, and then, from 2008–2011, for a copper plate etching titled Head of Jeremy King, which is now up for auction at Sotheby's. The price range for it is up to £350,000.

Lucian began frequenting the Caprice in the 1980s, and while he was always a significant part of my life, it wasn't until the Wolseley's opening in 2003 that King felt he had really gotten to know him.

“It was a place he would adopt as his home over the next eight years, and he became, over time, the only person I would sit with in the restaurant except my immediate family … I think we were drawn together because we were both quite solo people, both great observers, and there was no better place to watch the world go by than the grand cafe that was the Wolseley. We would enjoy our time together talking about our families, his peers, the past, or by singing, or saying nothing at all.”

Oliver Barker, the chairman of Sotheby's Europe, described the subject of the painting as "two absolute masters of their respective arts."

“While we will never know what Freud’s intended printed etching would have looked like, this luminous copper plate, replete with the artist’s meticulous scratches and chalk marks, is an artistic triumph in its own right.”

Thanks to Harriet Sherwood at The Guardian whose reporting provided the original basis for this story.