Military uniform
Logistics: Mass-produced uniforms are a good way to equip thousands of soldiers quickly and efficiently. Uniforms in standard sizes and designs are also easier to replace on campaign. As an example, English levies raised for service in Ireland or the Continent during the 17th century came to be provided with clothing purchased in bulk and often of a standard colour or cut. This was however only a temporary wartime expedient and the development of uniforms as such had to wait on the formulation of a system of permanent regiments, notably by the French Monarchy (see above).

Psychological warfare: The appearance of the troops was often enhanced in some way to intimidate the enemy. The tall, mitre-shaped caps worn by grenadiers in the 18th century made their wearers appear bigger and more impressive. King Frederick William I of Prussia had a guard unit of especially tall men with tall mitre hats, the Potsdam Giants. Prussian hussars wore the "skull and crossbones" (Totenkopf) on their hats from 1740 to 1918. This tradition continues into the present day with nose art and fin flash on combat aircraft.
The warriors of ancient Sparta, normally known for their austere lifestyle, wore expensive red cloaks. Reportedly this was adopted as the only colour on which the spilled blood of their enemies would not leave stains. There is a popular myth that the historic red coat of the English soldier was adopted for the same reason (in fact, blood does show as a dark stain on red clothing and the British red coat originated as a historical accident, possibly as a result of the relative cheapness of madder red dyes at the time of the English Civil War in the mid-17th century).
Hair styles in military organisations usually follow civilian fashions, but sometimes certain features are associated with soldiers. In the late 19th century, the ornate beards and moustaches worn by the officers of the day, which complemented their rank and age, were also worn by socially equivalent civilians. In the 20th and 21st centuries, the "high and tight" haircut often distinguished low-ranking soldiers, particularly infantrymen, or, in the United States, Marines and Soldiers of all ranks. The principal purpose, however, of the "high and tight" is to prevent lice and promote general hygiene. Modern regulations against beards also ensure a good seal is made around the face when using a gas mask.

Components of military uniform: 

See also: Military uniform types

Other

Uniforms by country

Citations: 

General sources: Bueno, José María (1983), El Ejército de Alfonso XIII - La Infantería de Línea (in Spanish), Madrid: Barreira, p. 26, ISBN 84-86071-02-X
Elliott, Jane E. (2002), Some did it for civilisation, some did it for their country: a revised view of the boxer war, Chinese University Press, p. 126, ISBN 962-996-066-4, retrieved 28 June 2010
Kannik, Preben (1968), Military Uniforms of the World, London: Blandford P., ISBN 0713704829
Lanxin Xiang (2003), The origins of the Boxer War: a multinational study, Psychology Press, p. 207, ISBN 0-7007-1563-0, retrieved 28 June 2010 (scroll down to next page from 206 to get to 208)
Pfanner, Toni (March 2004), "Military uniforms and the law of war" (PDF), International Review of the Red Cross, 86 (853): 93–124, doi:10.1017/S1560775500180113, S2CID 144589400
Asquith, Stuart (1981), New Model Army 1645-60 (illustrated ed.), Osprey, p. 32, ISBN 9780850453850
Attribution
This article incorporates text from a publication now in the public domain: Atkinson, Charles Francis (1911). "Uniforms". In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 27 (11th ed.). Cambridge University Press. pp. 582–593.

External links: 
"Images of military uniforms". NYPL Digital Gallery.
Anne S. K. Brown Military Collection, Brown University Library
Company of Military Historians Website
{US} Civil War Old Photographs Page
U.S. Civil War Era Uniforms and Accouterments
Soviet and Russian Federation uniforms and insignias
The Evolution of Military Camouflage