The Lion Dog of Malta (1840)
by
Sir Edwin Landseer
This painting is sometimes identified, going back to the later 19th Century, as depicting a Maltese dog with its paw resting on the muzzle of a Newfoundland. (See, for example, this entry here at The Cultured Newf.) That sure looks, to me, like a St. Bernard rather than a Newf, but.... here it is anyway, for the sake of the historical record.
This painting was commissioned by Queen Victoria for her mother's birthday; the Maltese depicted here, named Quiz, was one of the dogs belonging to Queen Victoria's mother, the Duchess of Kent. This painting remains in the Royal Collection.