LONDON - Mark Paton, 44, has plead guilty to attacking Reynolds' portrait of 18th-century diarist and lexicographer Samuel Johnson with a hammer at the National Portrait Gallery in London. The painting is worth around 1.7 million pounds. Mark Paton, a homeless man, repeatedly hit the work of art and later admitted criminal damage and possession of a hammer with intent to cause criminal damage during a hearing at City of Westminster Magistrates Court. The gallery said it was confident the painting could be repaired.

Defense lawyer Euan MacMillan said, “He has nothing against Sir Joshua Reynolds or Samuel Johnson, the subject of the painting,” MacMillan said. District Judge Quentin Purdy ordered Paton to undergo psychiatric tests before sentencing.

Catherine Bromley, a spokeswoman, said, "The glass was broken and part of the canvas beneath damaged. We will not know until next week the cost of the repair. Because of the fame of the sitter and the artist it is one of the most important parts of the collection. It is a criminal investigation so we cannot speculate on the motive."

Sir Joshua Reynolds (July 16, 1723–February 23, 1792) was the most important and influential of eighteenth-century English painters, specializing in portraits and promoting the "Grand Style" in painting which depended on idealization of the imperfect. He was one of the founders and first President of the Royal Academy. George III appreciated his merits and knighted him in 1769.

Reynolds was born in Plympton St Maurice, Devon, on 16 July 1723, and apprenticed in 1740 to the fashionable portrait painter Thomas Hudson [1701-1779], with whom he remained until 1743. From 1749 to 1752, he spent over two years in Italy, mainly in Rome, where he studied the Old Masters and acquired a taste for the "Grand Style". From 1753 on, he lived and worked in London. He became a close friend of Dr Johnson, Oliver Goldsmith, Edmund Burke, Henry Thrale, David Garrick and fellow artist Angelica Kauffmann [1741-1807]. He was one of the earliest members of the Royal Society of Arts: he encouraged that society's interest in contemporary art and, with Gainsborough, established the Royal Academy as a spin-out organization.

With his rival Thomas Gainsborough [1727-1788], he was the dominant English portraitist of the second half of the 18th century. Reynolds painted in more of an idealized fashion than his rival. Reynolds was a brilliant academic. He was of the opinion that "invention, strictly speaking, is little more than a new combination of those images which have been previously gathered and deposited in the memory." In 1789 he lost the sight of his left eye, and on 23 February 1792 he died in his house in Leicester Fields, London. He was buried in St. Paul's Cathedral.