Frederick also almost married Lady Diana Spencer, daughter of Charles Spencer, 3rd Earl of Sunderland and Lady Anne Churchill. Lady Diana was the favourite grandchild of the powerful Sarah, Duchess of Marlborough. The duchess sought a royal alliance by marrying Lady Diana to the Prince of Wales with a massive dowry of £100,000. The prince, who was in great debt, agreed to the proposal, but the plan was vetoed by Robert Walpole and the king. Lady Diana soon married John Russell, 4th Duke of Bedford.