The Ceremony of Beating Retreat
The actual origin of this ceremony remains obscure but there is no doubt that it was one of the earliest to be instituted in the British Army. One of the first references to the ceremony, which was then called 'Watch Setting', was made in the 'Rule and Ordynaunces for the Warre', circa 1554.
It appears that the original 'call' was beaten by drums alone, and that it was some years before the fifes were introduced. The bugle came at a later date still, and the present ceremony of having a band paraded is a modem innovation, which is purely used as a spectacle.
In days gone by, the hours of darkness brought a cessation of hostilities until the following day. The object of the call was to rally the guards necessary to secure the encampment for the night. It was also a warning for those outside the encampment or garrison to retire or else they would be kept outside until the next morning.
There is often confusion between a 'Retreat' and a 'Tattoo', The distinction was made in the General Orders of the Duke of Cumberland; 'the Retreat is to be beat at Sunset', whereas 'the Tattoo is to be beat at ten, nine or eight o'clock at night'.
In 1799 the 'General Regulations and Orders for the Conduct of HM Armed Forces in Great Britain' laid down that it shall be 'beat at sunset' and this is repeated in all editions of King's (and Queen's) Regulations down to the present day.