Ronald (Ronnie) Kray (24 October 1933 – 17 March 1995) and Reginald (Reggie) Kray (24 October 1933 – 1 October 2000) were English identical twin brothers and organised crime figures who operated in the East End of London from the late 1950s to 1967. With their gang, known as the Firm, the Kray twins were involved in murder, armed robbery, arson, protection rackets, gambling and assaults. At their peak in the 1960s, they gained a certain measure of celebrity status by mixing with prominent members of London society, being photographed by David Bailey and interviewed on television.

The Krays were arrested on 8 May 1968 and convicted in 1969 as a result of the efforts of detectives led by Detective Superintendent Leonard "Nipper" Read. Each was sentenced to life imprisonment. Ronnie, upon being certified insane, was committed to Broadmoor Hospital in 1979 and remained there until his death on 17 March 1995 from a heart attack; Reggie was released from prison on compassionate grounds in August 2000, five weeks before he died of bladder cancer.