'Cashelmara' is a historical saga novel by Susan Howatch.
Edward, a 60-year-old widower, falls in love with Marguerite, a 17-year-old American distant cousin. He brings her to the UK to marry her.
His home is Cashelmara, an Irish estate, during the Irish potato famine of the 19th century, giving a background to the book of tragedy and raw anger. Edward's son Patrick inherits the estate and similarly marries a young American girl, but there the similarities end since Patrick turns out to be a gambler who should never have married.
Some very unpleasant scenes and violence made this book rather distasteful in places, although I still found myself eager to keep reading.
This is one of Susan Howatch's earlier (and longer) books, written in her distinctive style with each section written from a different viewpoint, gradually revealing more as the novel progresses.