Boris Johnson knew a certain amount about his diverse family background, but was intrigued by several family stories and mysteries. He was particularly keen to investigate stories associated with the relatives of his paternal grandparents.

Boris's grandfather, Wilfred Johnson, had never spoken about the murder of his Turkish father in the 1920s. Boris’s grandmother Irene Johnson (née Williams), known as 'Granny Butter', had always been the subject of derision in the family due to her grandiose claims of an aristocratic French background.

So Boris set out on an international journey of discovery to separate fact from fiction.