Vajiravudh, an absolute monarch, he ruled and reigned from 1910 until 1925. He was one of the sons of King Chulalongkorn, the modernizing Siamese monarch introduced to non-Thai specialists in Rogers and Hammerstein’s The King and I.
He was educated in Siam at Bangkok and in Great Britain at Oxford and Sandhurst. Early in his rule, he formed a paramilitary organization, the White Tiger Corps, to build popular support for himself. Like his father, he, too, was a Westernizer, decreeing all Siamese take surnames, supporting compulsory primary education and unsuccessfully promoting adoption of Western clothing and hair dressing styles by Siamese women. After Siam’s successful participation in the war against the Central Powers, he and his foreign minister, Devawongse, renegotiated Siam’s unequal treaties with the imperialist powers in the 1920s. These renegotiated treaties restored Siamese fiscal and judicial autonomy, abolishing extraterritoriality.