Commentary Purg VII 124-129

Charles and Pedro, themselves noble of spirit, share the disgrace of degenerate offspring, the former's son, Charles II, king of Naples and count of Provence (1289-1309), singled out as being particularly vile.  See Grandgent's (DDP Grandgent.Purg.VII.127) explanation of these lines: 'Charles II is as much inferior to Charles I as Charles I is to Peter [i.e., Pedro] III.  Beatrice of Provence and Margaret of Burgundy were the successive wives of Charles I, Constance (daughter of Manfred) was the wife of Peter; and Charles I was not a devoted husband.  "The plant (the son) is inferior to the seed (the father) to the same extent that Constance boasts of her husband (Peter) more than Beatrice and Margaret boast of theirs (Charles)."'  Dante, who has somewhat surprisingly treated Charles of Anjou with a certain dignity (see the harsh characterizations of him at [Purg XX 67-69] and [Par XIX 127]), now takes some of that away, as Pedro and Charles are no longer treated with equal respect.  Porena (DDP Porena.Purg.VII.127-129) explains that Dante's gesture here is meant to show his objectivity; having saved Manfred (Purg. III), he now also saves Manfred's persecutor, Charles, despite his own political (and moral) disapproval.