This famous painting is called "The Blue Boy". It was painted by Sir Thomas Gainsborough. It is now located in the Huntington Library, San Marino, California.

It is a historical costume study as well as a portrait. The youth in his 17th-century apparel is regarded as Gainsborough's homage to Anthony van Dyck, and in particular is very close to Van Dyck's portrait of Charles II as a boy.

This very painting is a great representation of Thomas Gainsborough's style: all his works were painted in light colors and with easy strokes. The unique play of shadow and light is also present. He was also a talented landscape painter, that's why the artist paid a lot of attention to the backgrounds of his portraits, as we can see in this picture.

In a move that caused a public outcry in Britain, it was sold in 1922 to the American railway pioneer Henry Edwards Huntington for $728,800 (£182,200), a then-record price for any painting (which would be over $8.5 million in 2014).

More Info: en.wikipedia.org