Tying the knot: an expression that for most of us evokes happy memories of one of the best days of our lives. However, the fun of planning the wedding and the heady excitement of the first weeks of marriage will not be the experience of 13.5 million girls this year. Instead, fearing threats, and encouraged or coerced into marriage as a means of protection, nearly one-in-three girls in developing countries will marry before the age of 18.