Mary Portas: It’s the 1990s: Britpop is dominating the charts, Kate Moss and Naomi Campbell are on the cover of every glossy magazine and British fashion is ripe for reinvention. Leading the charge is a 20-something Mary Portas who has been brought in to revitalise the department store Harvey Nichols, at the time more likely to be associated with dowagers than daring designers.

With two babies at home, a sceptical, all-male senior management team to impress, and pressure to bring in new brands and customers, Mary steps into a world she doesn’t fully understand. At first it shows, but that vulnerability quickly reveals itself as vision.

By the millennium, the store would be renowned for its outrageous, headline-grabbing, traffic-stopping window displays; patronage by style icon Lady Di and bolly-swigging duo Patsy and Edina of the iconic sitcom Ab Fab – no longer fusty old Harvey Nicols but Harvey Nicks, daaarling!

Part memoir, part manifesto for business as a creative act, I Shop, Therefore I Am is the story of how she did it.