It is universally acknowledged that the suit is associated with two things—masculinity and work.  However, since Marlene Dietrich's iconic role as the cabaret singer Mademoiselle Amy Jolly in Josef von Sternberg's Morocco in the 30s, the phase of conforming to gender stereotypes was surpassed and this officewear staple was brought to life. Following the debut of Yves Saint Laurent's 'Le Smoking' suit in 1966, power dressing has since turned heads on both catwalks and the red carpet. Many leading ladies of the silver screen and the fashion industry have attempted to don this boundary-breaking look, but only a handful managed to blow us away for their effortless take on a menswear staple. From Katharine Hepburn to Tilda Swinton, here are our favourite women in suits.