investigation In 1880, Warren returned to England to become Chief Instructor in Surveying at the School of Military Engineering. He held this post until 1884, but it was interrupted in 1882, when the Admiralty sent him to Sinai to discover what had happened to Professor Edward Henry Palmer's archaeological expedition. He discovered that the expedition members had been robbed and murdered, located their remains, and brought their killers to justice. For this, he was created a Knight Commander of the Order of St Michael and St George (KCMG) on 24 May 1883 and was also awarded an Order of the Medjidie, Third Class by the Egyptian government. In 1883, he was also made a Knight of Justice of the Order of St. John of Jerusalem, and in June 1884 he was elected a Fellow of the Royal Society (FRS). Bechuanaland Expedition In December 1884, by now a lieutenant-colonel, Warren was sent as HM Special Commissioner to command a military expedition to Bechuanaland, to assert British sovereignty in the face of encroachments from Germany and the Transvaal, and to suppress the Boer freebooter states of Stellaland and Goshen, which were backed by the Transvaal and were stealing land and cattle from the local Tswana tribes. Becoming known as the Warren Expedition, the force of 4,000 British and local troops headed north from Cape Town, accompanied by the first three observation balloons ever used by the British Army in the field. The expedition achieved its aims without bloodshed, and Warren was recalled in September 1885 and appointed a Knight Grand Cross of the Order of St Michael and St George (GCMG) on 4 October 1885. Commissioner of Police In 1885, Warren stood for election to Parliament as an independent Liberal candidate in the Sheffield Hallam constituency with a radical manifesto. He lost by 690 votes and was appointed commander at Suakin in 1886. A few weeks after he arrived, however, he was appointed Commissioner of Police of the Metropolis following Sir Edmund Henderson's resignation. The exact rationale for the selection of Warren for the post is still unknown. Up to that time, and for some time into the 20th century, the heads of Scotland Yard were selected from the ranks of the military. In Warren's case, he may have been selected in part by his involvement in discovering the fate of Professor Palmer's expedition into the Sinai in 1883. If so there