John Singer Sargent (1856–1925)
He was an American expatriate artist, considered the "leading portrait painter of his generation" for his evocations of Edwardian-era luxury. He created roughly 900 oil paintings and more than 2,000 watercolors, as well as countless sketches and charcoal drawings. His oeuvre documents worldwide travel, from Venice to the Tyrol, Corfu, the Middle East, Montana, Maine, and Florida.
For a full biography got to https://en.wikipedia.org/wiki/John_Singer_Sargent