37. The British Army for decades required its soldiers to wear mustaches
In 1860 the King’s Regulations for the British Army stipulated that beards were out, hair was to be kept short, and the upper lip was not to be shaved. The regulation was intended to create a threatening appearance to the natives around the empire, especially in India and among the various Arab tribes which were under the control of the British. In 1916 the regulation was dropped due to the expedient of needing to equip the troops with gas masks in the trenches of World War One. The mustaches had been found to prevent a seal of the mask around the face of the wearer.