He later studied at Wellington College (1895-1899) and the Royal Military College, Sandhurst, from where he was commissioned onto the Unattached List of the Indian Army on 28 July 1900. He was admitted to the Indian Army on 26 October 1901 and was attached to the 17th Bengal Lancers. He was promoted to lieutenant on 28 October 1902 and transferred to the 32nd Sikh Pioneers on 1 March 1903. He obtained a transfer to the Foreign and Political Department on 24 January 1906. During a mission in Sikhim, he began to study Tibetan and became so proficient that he accompanied Francis Younghusband in his 1904 invasion of Tibet. He then served as the British Trade Agent in Gyantse (Tibet) at intervals between December 1905 and December 1909.