The crowds begin as one approaches the rear of the building: a long line, snaking back on itself contains those hopeful of gaining one of the 500 tickets on sale each day; further on, is a smaller queue of the luckier ones who had snapped up all the online tickets during the first three days of sale. Overall, the crowds are well behaved—for this is England—and approach their goal with good humor and a touch of the spirit of Dunkirk as they descend upon the National Gallery’s runaway success, Leonardo: Painter at the Court of Milan. It is not a large show, only some sixty paintings and drawings, but then Leonardo only began a score of paintings in a career spanning four decades. Of those paintings, fifteen autograph works survive, and four of these are generally deemed incomplete. To assemble almost every surviving painting from Leonardo’s Milanese period in London is a notable achievement, and these works are supplemented by others associated with his followers and sometime collaborators in the most sustained period of productivity in the artist’s life.