Art historyThe overlooked painting that unlocks ImpressionismWhile many have focused on Monet's Impression, Sunrise as a key Impressionist painting, another image was pivotal to the movement that launched 150 years ago.CultureThe childhood WW2 trauma that inspired Yoko OnoAs a major retrospective of the conceptual artist's work opens, her son Sean Ono Lennon talks about her art – and her collaborations with his father, John Lennon.CultureWhat the purple dress in Oprah's portrait meansA new portrait of Oprah Winfrey has just been unveiled in Washington DC. It draws on symbols used by the Old Masters, and hints at the unexpected origins of the colour purple.CultureThe masterpieces that helped Henry VIII pick wivesHans Holbein the Younger acted as a matchmaker to Henry VIII, painting portraits of potential wives in a bid to safeguard the future of the throne.CultureHow a 1574 portrait was made 'Insta-fabulous'Restorers are uncovering "forgotten faces" that were later retouched, with painters adding plump lips, sculpted noses and tapered chins centuries afterwards, writes Kelly Grovier.CultureThe painting that flouted sexual normsBy subverting a formal marriage portrait, showing a woman painted in male attire, the painter John Singer Sargent shocked viewers, writes Cath Pound.CultureThe masterpiece that became a memeWith Jimi Hendrix paintings, wall murals and even biscuit tins inspired by it, the 1624 painting The Laughing Cavalier still reverberates today, writes Deborah Nicholls-Lee.CultureWhen 'fairy mania' gripped Britain"Fairycore" may be trending on social media today but 100 years ago supernatural sprites were a national obsession. Holly Williams explores fairy fever.CultureThe most audacious painters of allAn art movement of "Wild Beasts" had a woman problem in more ways than one, writes Deborah Nicholls-Lee.Culture