Marianne Faithfull, the British singer and actress who achieved fame in the 1960s with her chart-topping single "As Tears Go By," has died at 78, a spokesperson said Thursday.

The singer, who had a long relationship with Sir Mick Jagger at the height of her fame, also carved out a career as an actress.

The singer and actress, who embodied the Swinging Sixties and performed for decades afterward, exuded an effortless cool.