At the beginning of the First World War, Joseph Pilates was imprisoned in England along with many Germans who happened to be living at the time in and around Lancaster, England. He was a German national who had been boxing and performing in England prior to 1914. While living in the Camp, he taught other residents the series of exercises that he had developed for personal use over the preceding decades both in Germany and in England. His own exercise sets drew strongly from his studies of yoga and Zen, as well as ancient Roman and Greek exercise regimens.