Commentary Par III 118

Her name, Constance, plays with and against her former weakness, inconstancy, in that, if she was inconstant in her vows when forced (as she was at least in Dante's sense of her life) back into the world, she was also constant in her heart ([Par III 117]).  It is also interesting that there are reports that the name assumed by Piccarda, in the convent of the Clarisse, was Constance (see DDP Lombardi.Purg.XXIV.10 and DDP Lombardi.Par.III.49).  In [Purg III 113] Constance is remembered with great affection by her grandson, Manfred (like his grandmother in this, not mentioning the name of the magnificent but hated 'last of the Roman emperors,' Frederick II [Conv.IV.iii.6]).  As was suggested (C.Purg.III.143), that canto is also a 'canto of two Constances.'