Joffre dissapears after season 1, and at some stage after Juan dies Alexander mentions that Cesare is his only son. So did they ever broach the subject of Joffre or is it one of those details just skimmed over? Does anyone knows an episode where they explain what happaned to Joffre? I know IRL Joffre outlived both Cesare and Alexander, but I also know 'The Borgias' isnt supposed to be historically accurate.