The Duke's Children

Lady Glencora, the wife of Plantagenet Palliser, the Duke of Omnium, dies unexpectedly, leaving the Duke to deal with their grownup children, with whom he has a somewhat distant relationship. As the government in which he is Prime Minister has also fallen, the Duke is left bereft of both his beloved wife and his political position.
Before her death, Lady Glencora had imprudently given her secret blessing to her daughter Mary's courtship by a poor gentleman, Frank Tregear, a friend of Lord Silverbridge, the Duke's older son and heir. Wikipedia