On 4 May 1980, seven terrorists holding twenty-one people captive in the Iranian Embassy in London's Prince's Gate, executed their first hostage. They threatened to kill another hostage every thirty minutes until their demands were met. Minutes later, armed men in black overalls and balaclavas shimmied down the roof on ropes and burst in through windows and doors. In seconds all but one of the terrorists had been shot dead, the other captured. For most people, this was their first acquaintance with a unit that was soon to become the ideal of modern military excellence - the Special Air Service regiment. Few realized that the SAS had been in existence for almost forty years, playing a discreet, if not secret, role almost everywhere Britain had fought since World War II, and had been the prototype of all modern special forces units throughout the world. In The Regiment, Michael Asher - a former soldier in 23 SAS Regiment - examines the evolution of the special forces idea and investigates the real story behind the greatest military legend of the late twentieth century.