He served the Colonial Service in Kenya from 1894 until his retirement in 1921 and published a number of monographs on a variety of subjects.
The son of an Indian Civil Servant, Hobley underwent technical education in engineering at Mason College (now the University of Birmingham).
He joined the Imperial British East Africa Company and was sent to Mombasa in 1890, where he served as Transport Superintendent at the coast.
He undertook a general tour of the whole of the Central African Lake Region (1895–96) and first arrived at Mumias in February 1895, where he established a British administration station along Sclater's Road.
During the First World War, he served as Chief Political Officer to the British forces in what was later named Tanganyika Territory.