Regimental flags of the British Army, historically described as ‘Colours,’ are consecrated and display insignia worn by soldiers of the respective unit along with the unit’s Honorary Distinctions or ‘Battle Honours’.
Historically the primary role of a regiment's Colour was to provide a rallying point on the battlefield, which was vitally important because without the forms of communications available to troops operating on a modern battlefield it was all too easy for soldiers to become disoriented and separated from their unit during conflict. For soldiers to recognise their Regiment's Colour, it was necessary to display it; this was accomplished by young officers marching between formed-up ranks of soldiers with the Colour held high, which is the origin of the term ‘trooping'. What is today a great ceremonial spectacle began life as a vital wartime parade.
The ceremony of Trooping the Colour is believed to have been performed first during the reign of King Charles II (1660 – 1685). In 1748, it was determined that this parade should mark the official birthday of the Sovereign, becoming an annual event when George III ascended the throne in 1760.
The King’s Colour of a battalion of Foot Guards is trooped each year in front of the Sovereign. Only one Colour can be trooped at a time and the five regiments of Foot Guards – Grenadier, Coldstream, Scots, Irish and Welsh Guards – take turns to do so annually. The spectacular ceremony of Trooping the Colour remains the single national celebration of the Sovereign's Official Birthday.