A look at the grounds of the UK's most renowned palaces, revealing the stories behind the opulent gardens at St James's and Kensington, which were created by kings and queens for their own pleasure then opened to the public as royal parks. Kate Williams delves into some of the shocking and grisly history of royal gardens, including a murder by boiling oil in a terrifying siege during the 13th century reign of King John, in what is now the Moat Garden of Windsor Castle