This oil portrait of an old sailor dates from 1832, when he was just 22 years old.
The paintings of Købke (pronounced keub-kuh) were penetrating and uncompromising in their realism, placing him in the company of Thomas Eakins, Adolf von Menzel, Ivan Kramskoi, and John Constable. 
Købke was active in the 1830s, during Denmark’ Golden Age. This was the time of Hans Christian Andersen and Søren Kierkegaard. 
Why is he not better known? His paintings are very small (the sailor portrait is 12 x 10 inches); they show modest subjects; he didn’t sell paintings or otherwise engage with the critical establishment or the marketplace; few of his paintings left Denmark; and he died fairly young.There’s a good book in English on him written by Sanford Schwartz (Timken Publishers, 1992) though the reproductions are small on the page.
Wikipedia
Exhibit through June 13 at London's National Gallery. (Video included on link).
