The first World Jamboree was held in 1920 in London, England at the Olympia Arena. Approximately 8000 scouts from 34 nations attended the event. Baden-Powell, the founder of Scouting, was of course present, and he was proclaimed Chief Scout of the World at this event. They have been held essentially every four years since then with the exception over the years of World War II. There has been a medical presence at every World Jamboree, but there is not, to my knowledge, medical memorabilia from every event. The blue buttons below link to pages for which there is something medical.