Well let's not forget that the Borgia family were originally from Spain before they moved to Italy, and according to history, after the downfall of the family, Cesare was imprisoned in Spain, after he escaped imprisonment he lived the last few years of his life in Spain. So it's only natural for him to be buried in Spain, considering his Spanish heritage and Spain was the last place where he spent his last years in. Although it is sad that he was not buried with Lucrezia but at least he is buried in the same church as their father Rodrigo in Spain.

Traditionally married couples are suppose to be buried next to each other, and after Lu's third marriage to Alfonso d'Este the duke of Ferrara, she became part of the Este family, so when she died she was buried next to her husband and several other members of the Este family in Italy.

I still need to read Puzo's novel again to refresh my memory, there's a lot in the book that I have forgotten, but I vaguely remember in the novel, Lu inherited some of Cesare's possessions after his death, including his sword, which was very significant. Normally the widowed spouse would inherit the possessions and assets of their deceased husband or wife, but in Puzo's novel, Lu inherited Cesare's possessions, proving that while the siblings were both legally married to other people at the time, but emotionally and spiritually, the siblings loved each other like they were each other's true spouses And that's how Cesare & Lu's incestuous relationship is generally portrayed in popular culture, in most if not all fictional adaptations about the Borgia family, Cesare & Lu's relationship is always portrayed as incestuous. And while they're both legally married to other people on paper only, but deep down emotionally and spiritually, Cesare & Lu loved each other like husband and wife, they were each other's real spouses

I believe that's one of the many reasons why people started the whole incest rumor between them, and from then on many rumors came out to the point that some even said that before Lucrezia was with her first husband Cesare and Lucrezia were together and Rodrigo witnessed and all this crap that I honestly don't believe is true.

I like to think Cesare/Lucrezia were closer to Los Borgia version. Meaning they never went to bed but they definitely loved each other the most and maybe even romantically. I also like to think Cesare was a prick with everyone else except with her which also happens in Los Borgia.

If I go to Borgia, that's very complicated, because I like the way they portrayed the relationship at the end but not in the beginning and also they had Cesare crazier which is cool I guess but I like to think Cesare was smarter and less insane than Borgia's.

that sounds more like Francois' version in The Borgias...while Francois' Cesare definitely had his sadistic and violent side to him, but unlike the Cesare in 'Borgia', Francois' version of the character was also much more calm and collected, level-headed and smarter in comparison. I think Francois' Cesare was also more mature and wiser overall than Mark Ryder's version...maybe that's because Francois' Cesare was older in The Borgias, while Mark's Cesare was younger in Borgia.

I really love how Cesare & Lu's relationship was portrayed in the Showtime version because their relationship was written much more consistently and solid from the beginning to the end in The Borgias, and not to mention the awesome chemistry between Francois & Holly these reasons made their incestuous connection between the siblings so believable and compelling in The Borgias the incest really was not well written nor carefully thought out in Borgia.