Beyoncé Knowles has always been sexy: naturally and consciously so. But her sexiness – those astonishing bottom-swooshing dance moves; the gleaming, undulating chest; the ever-changing, lustrous locks – sat alongside a moral substance that grew as her career progressed. She weighed in on politics, raising $4 million for Barack Obama and singing at his first inaugural ball. She weighed in on sexual morality, telling women in one of her most iconic songs that their man ought to, if he was to be taken seriously, ‘put a ring on it’. She is a committed Christian, having grown up in a Methodist household and frequently spoken of her faith. And she is one of the world's greatest marriage evangelists, calling her 2013 tour ‘The Mrs Carter Show’ in a nod to her husband Jay-Z’s name, and telling newspapers she’d only had one boyfriend before marriage who she didn’t even do ‘you know’ with.