The king came to believe that the real threat to Siam came from the French, not the British. The British were interested in commercial advantage, the French in building a colonial empire. They occupied Saigon in 1859, and 1867 established a protectorate over southern Vietnam and eastern Cambodia. Rama IV hoped that the British would defend Siam if he gave them the economic concessions they demanded. In the next reign this would prove to be an illusion, but it is true that the British saw Siam as a useful buffer state between British Burma and French Indochina.