Details

red square with a bold, equilateral white cross in the center that does not extend to the edges of the flag; various medieval legends purport to describe the origin of the flag; a white cross used as identification for troops of the Swiss Confederation is first attested at the Battle of Laupen (1339)

note: in 1863, a newly formed international relief organization convening in Geneva, Switzerland sought to come up with an identifying flag or logo; they chose the inverse of the Swiss flag - a red cross on a white field - as their symbol; today that organization is known throughout the world as the International Red Cross