Valerie Hermann, chief executive of Yves Saint Laurent, has brought light to the venerable French fashion house.

Since Ms Hermann's appointment less than three years ago, the label's creative director Stefano Pilati has prised open the dark store spaces created by his predecessor, Tom Ford. And YSL is emerging, too, from a black hole on the balance sheet of its parent Gucci Group. After 10 years of losses, YSL is starting to see a glimmer of sunlight at the end of the tunnel.