<P> The third incident occurred in September, when two men were detained while on a sand bank of the Thukela River near the Middle Drift . Sir Bartle Frere described this matter in a despatch to Sir Michael Hicks Beach, who had replaced Carnarvon as Secretary of State for the Colonies: </P> <Dl> <Dd> "Mr. Smith, a surveyor in the Colonial Engineer Department, was on duty inspecting the road down to the Tugela, near Fort Buckingham, which had been made a few years ago by order of Sir Garnet Wolseley, and accompanied by Mr. Deighton, a trader, resident at Fort Buckingham, went down to the ford across the Tugela . The stream was very low, and ran under the Zulu bank, but they were on this side of it, and had not crossed when they were surrounded by a body of 15 or 20 armed Zulus, made prisoners, and taken off with their horses, which were on the Natal side of the river, and roughly treated and threatened for some time; though, ultimately, at the instance of a headman who came up, they were released and allowed to depart ." </Dd> </Dl> <Dd> "Mr. Smith, a surveyor in the Colonial Engineer Department, was on duty inspecting the road down to the Tugela, near Fort Buckingham, which had been made a few years ago by order of Sir Garnet Wolseley, and accompanied by Mr. Deighton, a trader, resident at Fort Buckingham, went down to the ford across the Tugela . The stream was very low, and ran under the Zulu bank, but they were on this side of it, and had not crossed when they were surrounded by a body of 15 or 20 armed Zulus, made prisoners, and taken off with their horses, which were on the Natal side of the river, and roughly treated and threatened for some time; though, ultimately, at the instance of a headman who came up, they were released and allowed to depart ." </Dd> <P> By themselves, these incidents were flimsy grounds upon which to found an invasion of Zululand . Bulwer did not initially hold Cetshwayo responsible for what was clearly not a political act in the seizure and murder of the two women . </P>

What were the causes of the zulu war