The flag of Bulgaria is a tricolour consisting of three equal-sized horizontal bands of (from top to bottom) white, green, and red.

The Bulgarian flag was first adopted after the Russo-Turkish War (1877–1878), where Bulgaria gained independence. The national flag at times was charged with the state emblem, especially during the People’s Republic of Bulgaria. The current flag was re-established with the 1991 Constitution of Bulgaria and was confirmed in a 1998 law. Wikipedia