All the important items I must bring to England

Tonight I started getting ready for my upcoming journey to England. I got out my suitcase, my guide books, my pens, paints and paper and a few incidentals. I pride myself on being a modern traveler and having all the latest traveling necessities. I still need to locate my parasol, my extra pair of gloves and my box camera. Do you have any helpful suggestions for me as to what else I need to bring along for a Spring sketching and painting trip to S.E. England? Your help will be appreciated.