We all take for granted that the hammerbeam roof of Westminster Hall (see https://www.parliament.uk/about/living-heritage/building/palace/westminsterhall/architecture/the-hammer-beam-roof-/) is a true masterpiece of medieval workmanship and innovation. Many of us know that the transformation of the (then) huge building was at the instigation of Richard II. But how many of us know of a painting that captures a fleeting…