Hurdis Ravenshaw was born in June 1869 to John Hurdis Ravenshaw and his second wife Harriet Lalande Biggs. His elder half-brother was Thomas Edward Ravenshaw. He was educated at Haileybury and Imperial Service College and from there joined the militia, using this posting to gain a commission in the East Yorkshire Regiment in December 1888. Seeking action, in August 1890 he transferred to the Devonshire Regiment who were sent to India and went on campaign in 1895 as part of the Chitral Relief Force which overthrew the Mehtar of Chitral and replaced him with the pro-British Shuja ul-Mulk the younger son of the former ruler, Aman ul-Mulk. In 1897 and 1898 Ravenshaw was again active, conducting operations against Malakand and then participating in the Tirah Campaign where he was with the army which forced the Khyber Pass against the Afridis. In 1899 he was transferred with his regiment to South Africa to fight against the Boers at the outbreak of the Second Boer War. As Adjutant of the regiment, Ravenshaw fought in the relief of Ladysmith and numerous smaller actions for three years. On his return home, Ravenshaw was given the position of Adjutant at Sandhurst, a post he held until 1907.
In 1914, Ravenshaw was brought out of semi-retirement to command the 1st battalion of the Connaught Rangers, an Irish regiment in India which he brought to France for service on the Western Front in late September. Ravenshaw remained in command of the Connaught Rangers until April 1915, when he was made a staff officer at 1st Division headquarters before being promoted and given command of the 83rd Brigade. This unit saw action in France during 1915 before being sent to Salonica in Greece as part of the Mediterranean Expeditionary Force. There he served against the Bulgarian Army, rising to command the 27th Division in October 1916. In December 1916, whilst sailing to England to meet superiors, his ship was sunk by an Austro-Hungarian U-boat and he with his adjutant Captain FHD Vickerman were captured and taken to Austria-Hungary, where they remained in captivity for the next two years. Released following the armistice, Ravenshaw retired from the armed forces. In 1920 he travelled to Port Elizabeth in South Africa and on 6 June was seen entering Addo Bush near the city but failed to return. A search party discovered his body two days later.
