On 19 November 1878 Blackman was a 22 year old Sergeant when he landed ashore at Durban as part of ‘Active’s” Naval Brigade for the Zulu War. As Sergeant, Blackman would have been second in command of the Royal Marines, under Lieutenant Dowding. He served at Fort Pearson on the Lower Tugela until becoming part of Pearson’s Number One Column. He fought at the Battle of Inyezane, and accompanied the Column to Eshowe where he served as quartermaster for the Naval Brigade. In March Blackman was in the hospital at Eshowe where his condition was described as ‘bad’ by Commander Campbell who was in command of the Naval Brigade. In April 1879, after returning to Fort Pearson, Blackman was invalided from the Naval Brigade. In June he was sent back to England aboard HMS Orontes from Simon’s Bay. For his service, Blackman was awarded the South Africa Medal with clasp “1877-8-9.” (On the Medal Roll he is listed as W. T. Blackman.) In October 1879 he was present at the Banquet for the Navy and Army in Portsmouth where he was one of the speakers.