Lucrezia Borgia Series by Jean Plaidy

In a castle in the mountains outside Rome, Lucrezia Borgia is born into history's most notorious family. Her father, who is to become Pope Alexander VI, receives his first daughter warmly, and her brothers, Cesare and Giovanni, are devoted to her. But on the corrupt and violent streets of the capital the Borgia family are feared, and Lucrezia's father causes scandal, living up to his reputation of 'most carnal man of his age'... moreIn a castle in the mountains outside Rome, Lucrezia Borgia is born into history's most notorious family. Her father, who is to become Pope Alexander VI, receives his first daughter warmly, and her brothers, Cesare and Giovanni, are devoted to her. But on the corrupt and violent streets of the capital the Borgia family are feared, and Lucrezia's father causes scandal, living up to his reputation of 'most carnal man of his age'. As Lucrezia matures into a beautiful young woman, her brothers are ever more protective and become fierce rivals for her attention. Amid glorious celebrations their father becomes Pope, and shortly after Lucrezia is married - but as Borgias the lives of the Pope's children are destined to be marred by scandal and tragedy, and it's a fate that Lucrezia cannot hope to escape . .. less

Light on Lucrezia is the compelling story of a beautiful woman caught up in a tortuous web of fear and love. Born into Rome's notorious Borgia family, Lucrezia's life so far has been coloured by violence and betrayal. Now, married for the second time at just eighteen she hopes for happiness with her handsome husband Alfonso. But faced with brutal murder she's soon torn between her love for her husband and her devotion to her brother Cesare . ..