William Lamb was born the second son of the Viscount and Viscountess Melbourne, although his father realized that he had not in reality “sired” William. Indeed, of the Viscount’s six children, only the first, Peniston, sprang from the loins of his father. Having fulfilled her duty as a wife to provide her husband with a son and heir (Peniston), Lady Melbourne used her personal charms to further her family's interests by having love affairs with powerful men. William’s father was actually the Earl of Egremont, and he apparently took pride in his son, whose picture he hung at Petworth.
After William and Caroline fell in love, it appeared they had no future, for William was a second son and would have to make his way in the world, while Caroline was an aristocrat whose mother hoped she might even marry the Prince of Wales. However, Peniston died of tuberculosis, and William returned to ask for Lady Caroline’s hand. They were married June 3rd, 1805. From that moment until Caroline finally passed away in January 1828, the couple lived in constant expectation that William’s father would die, leaving the Melbourne estate to his second son. But Lord Melbourne outlived his daughter-in-law by six months. It appears the elder man never completely got over the death of his first-born. He treated William with grudging respect and kept the couple on a relatively small allowance throughout his life.
William is usually portrayed as a long-suffering husband. Undoubtedly he was. However, he and Caroline formed such a solid bond that he refused to give her up, even when he might easily have done so. It appears that despite her numerous flings, he remained faithful to Caroline until the very last months of her life. By the standards of his class, this represents a truly unbelievable level of fidelity to one’s spouse, as William’s biographer Leslie Mitchell admits in some puzzlement. Once we acknowledge that their bond was abnormally tight, we can begin to make sense out of the fact that William refused for so long to be separated from her, and encouraged her writing career even when his friends and relatives were howling her down, standing ready (quite literally) with a doctor’s declaration of insanity and a straitjacket to cart her away. Even after he finally agreed to a legal separation in 1825, he couldn’t really go through with it, and he permitted Caroline to return to her beloved country home, Brocket Hall, where she lived out the remainder of her painful (but much calmer) days.
When Caroline died, William told Lady Brandon (with whom he had recently started an affair), that he felt “a sort of impossibility of believing that I shall never see her countenance or hear her voice again, and a sort of sense of desolation, solitude and carelessness about everything, when I forced myself to remember that she was really gone.”
William later survived not one but two prosecutions for “Criminal Conversation” (i.e., adultery) with women who found his reserved manner and taste for whipping difficult to fathom. He became the first Prime Minister under Queen Victoria and died in 1848.