'Beating Retreat' is an annual pageant of military music and marches on Horse Guards Parade. It's a magnificent example of the kind of pomp and pageantry that London does so well. It always takes place in the week before Trooping the Colour.
The ceremony dates back to the late 17th-century, when the beating of drums and lowering of flags signalled to the battlefield troops that the camp gates were about to close. These days it's more of a military concert with marching bands, and includes the lowering of the Regimental flag at sunset.
This year's pageant will be performed by the Massed Bands of the Household Division (which is drawn from the two Household Cavalry Regiments and the five Foot Guards Regiments).
The evening will end with a salute to the Queen (or possibly another high-ranking member of the Royal Family), followed by a fireworks display.
Horse Guards is quite a small seating area, and tickets are hard to come by. So if you want to attend Beating Retreat make sure you buy a ticket in plenty of time.