Ok, I have to wonder, did the duke maybe hit his head during the war and get amnesia or something? It's the only way I can understand him. Like he was at war, got knocked one too many times in the head, forgot he hated his fiance, someone had to explain to him that he had a fiancee back home, and he returned thinking he had someone who cared about him only to get handed the annulment papers. I mean, why else would he not know what her life was like? Why would he not be relieved to have the engagement annulled?