I have only just heard rather belatedly of the death of Matthew Rutenberg, who was one of the most widely knowledgeable art historians I have ever known. He was brought up in Florida – I once visited there – and claimed that his uncle had tried to buy the paintings off the walls of the National Gallery of Scotland, although, like some of his other stories, this was possibly fictitious. By the time he arrived as a student at Harvard, he had an encyclopedic knowledge of the history of western art, which he combined with taking courses in police studies. I was adopted as a friend and encouraged to go on a tour of every major American art museum accompanied by a guidebook which he supplied. When he came to study at the Warburg Institute, he quickly got to know all the dealers in spite of looking a touch disreputable and stayed for a time at our flat in Southwark reading through the night. I lost touch with him later when he was advising private collectors in New York and now it’s too late to see him again.