Blanche, which originated as a nickname for a pale blonde and then became associated with the notion of purity, was in style a century ago, ranking in the double digits until 1920. She then had to fight the stereotype of faded Southern belle, a la Blanche DuBois in Tennessee Williams's A Streetcar Named Desire and Blanche Devereaux in TV's Golden Girls. Now all three of the Golden Girls--Blanche, Rose and Dorothy--could be ready for revival, with Blanche sounding like a stronger, simpler alternative to Bianca.
A saint's name, Blanche was a royal name in France by the twelfth century, then was brought to England by the French wife of Henry I. One possible powerful namesake is Blanche Scott, one of the original daredevil aviatrixes.