Elizabeth "Elsie" Blackall Shapter was born in Exeter, England. On the death of their parents in quick sucession, she and her siblings were separated and Elsie was adopted. She attended private schools and then trained as a nurse and later as a midwife. In 1906, she married Leslie Duke Knocker, an accountant, with whom she had a son; they lived for a while in Singapore before divorcing. She shared a passion for motorcycles with her friend Mairi Chisholm, with whom she competed in races and sidecar trials. At the outbreak of World War I, the two friends volunteered as drivers for a Flying Ambulance Corps being sent to help the hard-pressed Belgian army. Frustrated by the death and suffering of soldiers in the field, they decided they could save more lives by setting up their own front-line first aid post. Its location at Pervyse, north of Ypres, gave rise to their nickname in the news media, "The Angels of Pervyse." They had to raise their own funds, as they were not connected with any established organization, and worked at the station for four years, mere yards from the fighting. In 1918, they were nearly killed by arsenic gas and had to return home. They were decorated by the King of Belgium and the British Army and were made Officers of the Order of the Hospital of St. John of Jerusalem. In 1916, Elsie married an aristocratic Belgian pilot and became the Baroness de T'Serclaes. However, the marriage fell apart when he learned that she had been previously married. At the start of World War II, she joined up again and became a senior officer in the Women's Auxiliary Air Force (WAAF) working with RAF Fighter Command. She published her memoirs in 1964.