There a multitude of flags that have been created to represent Oklahoma as a European territory, a United States territory and as a state. In 1541, Francisco Vásquez de Coronado, the New Spain Governor of New Galicia, was the first European to lay claim to Oklahoma land. In 1663, King Charles II gave parts of Oklahoma to his friends. In 1682, La Salle of France laid claim to other parts of Oklahoma in the name of the French king.
Later on, during the American civil war the Texas Rangers, who were fighting for the Confederacy, took over part of the territory of Oklahoma and flew a Rangers flag over the lands.
The publication The Oklahoman has the articles, “The Unfurling History Of Flags Over The State” and “State’s Fourteen Flags Show Historical Claims” that goes more in depth into the history of the Oklahoma flags.