The history of the Switzerland flag starts in the Middle Ages. Switzerland is a country made up of federal states, called Cantons. When these Cantons went to war, they had no common field sign or uniforms, therefore they used their own state flags when they joined in battle. However, this was confusing so the German emperor allowed them to use a red battle flag during the campaigns.
The Battle of Laupen (1339 a.d.) is when the Old Swiss Confederacy (1219-1515) is first allowed to use the white cross to denote their unity. The troops were allowed to sew onto their uniforms two stripes of white textile, to contrast the crosses used by other empires during that time. At the Battle of Arebo (1422 a.d.) an elongated, white cross was sewn onto a triangular, red field sign and used in battle. This is the first flag that represents the confederacy instead of the individual Cantons.
Throughout the 15th and 16th centuries, the flag was used in many battles, always with the battle-red background depicting a white cross. Around the year 1540 a.d., the Swiss pledged neutrality and the military ceased to take part in any battles. Consequently, the flag fell out of use.
The 17th century saw symbolic depictions of the Swiss flag without the white cross. Although, late in the 16th century, the individual Cantons adopted a flag based on the white cross design. It showed a bold, white cross to the edge of the field and the background was striped in their colors.
The Switzerland flag underwent some changes in the 1700s and 1800s before becoming what is known as the current flag of Switzerland. In 1798, an invasion led to the Helvetic Republic disposing of all previous flags and replacing them with a green, red, and yellow tri-color flag. That flag didn’t last long. In 1814, Tagsatzung reintroduced the flag with the red background and white cross. The flag had some minor adjustments, such as the addition of the cantonal coat of arms surrounding the white cross. On December 12, 1889, the dimensions of the flag were added to the Swiss constitution and the square red flag with the bold white cross became the national flag of Switzerland. It is one of only two square flags used today.