Ian,
Lance-Corporal J. Alexander, 17th (Duke of Cambridge's Own) Lancers.
The 17th Lancers were sent out after the disaster at Isandlwana. They served in a Cavalry Brigade under the command of Major General Frederick Marshall, and took part in the 2nd Invasion of Zululand.
The 17th Lancers were involved in some minor skirmishes during the advance to Ulundi, where King Cetshwayo kaMpande had his 'capital'. On 2nd June, elements of the 17th Lancers took part in the search for the body of the exiled Prince Imperial of France, who was killed in an ambush on 1st June, whilst serving as a 'volunteer' with the British forces.
The 17th Lancers' major engagement in the Zulu War was the Battle of Ulundi, which was fought on 4th July 1879.
For an account of the Battle of Ulundi, see my account on:
http://www.rorkesdriftvc.com/ulundi/index.htmJohn