In 1857, the National Gallery’s pioneering director Sir Charles Eastlake bought one of Veronese’s most sumptuous paintings, ‘The Family of Darius before Alexander’. The purchase was met with strident and very personal opposition from a Tory, Lord Elcho, in the House of Commons, but his objections were swatted aside by Lord Palmerston and we were spared the irony of fighting to defend the Indian empire while rejecting the opportunity to buy the finest painted celebration of imperial conquest.