The Oromo nation was free and had their own social, political and legal system. This system is called "Gadaa", and it is a system that has guided  political, economic, their philosophy, the religious, social,art, history and method of time keeping. In Gadaa system the Oromo society is grouped according to their age and undertake different responsibilities in different ages.

In Gadaa system, the Oromo practiced their own religion by worshipping Waaqa, which means God. Waaqa is one and the same for all. The religion affair is undertaken by Qaallu/Qaallitti (male/female) just as any religion leader (Bishop, Imam, Rabbi,). Qaallu/Qaallitti plays both a spiritual and political role in Gadaa system where different national ceremonies are organized and overseen by Qaallu/Qaallitti institution. It was also a repository of important ceremonial articles or collective symbols like in the Buttaa ceremony, the bokku (scepter), the national flag, etc.

The national flag is made in the colors of the Qaalluu torban (surri ruufa). The national flag has three colors: black at the top, red in the center and white at the bottom (all of them have the same size). In the Gadaa, the three colors black, red and white represented those yet to enter active life, those in active life and those who had passed through active life, respectively, in short we can say, the past, current, and future.