Tom Bower explains in his acknowledgements that this is not an authorised biography and he did not seek Boris Johnson’s co-operation. Instead, he followed his usual biographical method of interviewing well over 100 people who knew Boris, some named, some not. Obvious sources are his mother Charlotte, his sister Rachel, his first wife Allegra, his long-serving mistress Petronella Wyatt, but not his second wife Marina, nor his current fiancée Carrie Symonds.