[1] He subsequently joined the British Army and was commissioned a cavalry officer as second lieutenant in the 17th Lancers on 14 March 1900.
A fierce fight, subsequently to be known as the Battle of Elands River, took place with the Lancers being caught in a cross-fire and suffering heavy casualties.
Deneys Reitz, a younger commando member, encountered Captain Victor Sandeman, the Lancers' commander, and Vivian, who was his lieutenant, among the wounded.
[4] In his book Commando, Deneys Reitz, one of the Boers, recounts how Vivian pointed out his bivouac tent and told him it would be worth his while to take a look at it.
[6] Thomas Pakenham, in his introduction to the 1983 Jonathan Ball edition of Commando, reports a more elaborate story.