The colour was deemed eminently martial and war-like by the Romans, among whom the paludamentum, the military robe or cloak of a general, was scarlet, bordered with purple. Juvenal (vol. vi.) mentions officers clad in a scarlet dress, and according to Livy, such was also the attire of the lictors who attended the consul in war.
Scarlet is mentioned among the colours used by the Britons for dyeing their skins in the time of Julius Cæsar; but their favourite herb was glastum, or woad, called glas by the Celts, i.e., blue, that they might look dreadful in battle.
The red uniform of the British Army was adopted simply from the circumstance, that it was the royal colour of the kingdoms of England and Scotland, centuries before the union of the crowns or of the countries; red and blue being the royal livery of England, red and yellow the royal livery of Scotland. In the latter country, red has ever been the judicial colour, worn by the Lords of Council and Session, the magistrates of Edinburgh and other cities, as well as by the students of some of the universities.
The Royal Crowns of England and Scotland were always lined with scarlet, though James IV. for a time adopted imperial purple. The surcoat of the Knights of the Garter is crimson; and in the apparel of those of the Bath we find the surcoat, breeches and stockings all red, as directed at the revival of the Order by George I. in 1725.
Scarlet faced with blue was the uniform of the City Guard of Edinburgh, a corps which existed from the days of Flodden until those of Waterloo.
In England, scarlet and blue had long been the two chief colours of the cloth directed for the array of the king's troops; in the time of the Crusades the English wore white crosses; but Henry VIII. had troops in white with a red cross. From the commencement of the fourteenth century the Scots wore blue surcoats with white St. Andrew's crosses thereon. Scotch and English soldiers were wont in those days to taunt each other as Blue-coat and White-coat.
The Memoirs of Kirkaldy of Grange record an instance of this kind in a sham fight.
In the afternoon of the 2nd March, 1571, a party of Sir William Kirkaldy's soldiers were marched from Edinburgh Castle, which they approached again at 8 p.m., with white English surcoats over their armour. On drawing near they were challenged thus:
"Who are ye that trouble the Captain in the silence of night?"
"The army of the Queen of England," replied the mock assailants with a discharge of arquebusses. Blank volleys promptly responded from the walls, during which they freely bestowed upon each other the taunts and scurrility which the Scots and their Southern neighbours used in battle as liberally as hard blows.