Elizabeth Herbert, Countess of Pembroke and Montgomery (born Lady Elizabeth Spencer; January/March 1737 – 30 April 1831) was the second daughter of Charles Spencer, 3rd Duke of Marlborough and Elizabeth Trevor.
She was born Elizabeth Spencer to Charles Spencer, 3rd Duke of Marlborough and Elizabeth Trevor. Her siblings were George, Charles, and Diana.
In 1756, aged 19, she married Henry Herbert, 10th Earl of Pembroke. In 1762, he left her to elope with another woman.
"Husbands are dreadfull and powerful animals," wrote the long-suffering Elizabeth after reconciling with her husband in 1762. She refused to allow his illegitimate son from that affair to keep the surname Herbert, and she and Henry ended up living in separate quarters at Wilton (he downstairs, she upstairs).
She was admired by George III in the early 1760s, becoming a Lady of the Bedchamber to his wife, Queen Charlotte. The King and Queen stayed for two nights with Henry and Elizabeth at Wilton House in 1778.
She would eventually move to Pembroke Lodge in Richmond Park in 1788, which King George had put at her disposal. However, the King – who had been attracted to Elizabeth as long as he had known her – suffered his first bout of insanity that same year, and she had to endure the embarrassment of his sporadic and unwanted attentions until his recovery later that year.