Another illustrative example of industrial power projection, was the British Expedition to Abyssinia in 1868 as a retaliation against Emperor Tewodros II of Ethiopia's imprisonment of several missionaries and British government representatives. The expeditionary force sent was a tremendous logistical and technological challenge at the time. Commanded by Lieutenant-General Sir Robert Napier of the Bombay Army, military intelligence was used to estimate the required size of the army and the difficulties of traversing the inhospitable terrain.