Ravenna's powers are based on the legend of Erszebet (or Elizabeth) Bathory, a 17th-century Hungarian potentate who allegedly consumed and bathed in the blood of murdered young girls in an attempt to rejuvenate herself.
Rupert Sanders' insistence on realism in scale, meant minimal miniature model work. The huge castle in the enchanted forest, for example, took six months to construct. The gigantic trebuchet, consisting of a metal skeleton interior and wooden exterior, weighed 6.5 tons.
Charlize Theron tore a stomach muscle while shooting a scene which required her to scream very loud.
During filming, Kristen Stewart accidentally punched co-star Chris Hemsworth in the face, giving him a black eye. That take is used in the film.