The flag of the Kingdom of Thailand was adopted on September 28, 1917. The flag is rectangular with five horizontal stripes: the top and bottom stripes are red, the second stripes from the top and bottom of the flag are white, and the center stripe is blue. The center blue stripe is twice as wide as the others. King Vajiravudh (Rama VI), who ruled Thailand from 1910 until 1925, designed the flag.
The colors of the flag represent an unofficial motto of Thailand, “nation-religion-king:” red represents the Thai nation, white represents religion, and blue represents the Thai monarchy. Some sources claim that the blue represents support of the Allies of World War I, as many other countries in the alliance had red, white, and blue flags. Thailand adopted a naval flag in 1917 in addition to the national flag, which includes a red circle in the center of the national flag. In the center of the red circle is a white elephant, a symbol of royalty. The Kingdom of Thailand has many other military flags currently in use as well, which include the colors of the Thai flag and relevant military emblems.
The flag of Thailand dates back to the seventeenth century and were most likely plain red rectangular banners. During the Chakri Dynasty in the late eighteenth century, a white chakra—a disk-like weapon used by the god Vishnu and symbol of the Chakri Dynasty—was added to the flag. During the next dynasty, a white elephant was added inside the chakra to symbolize the royal monarchy. The chakra disappeared from the flag around 1855 with Rama IV dynasty, but the white elephant, decorated in varying amounts of regalia, remained in the center of the red flag until 1917. For a short time in 1917, Thailand used a red and white striped flag, but by the fall of that year, the flag included the blue stripe.