The infantry regiments were raised with men from the four provinces of the Union: the 1st Regiment troops were from the Cape. Also known as "The Cape Regiment." A Company (Western Province) was made up from men mostly from the Duke of Edinburgh's Rifles. B. Company was recruited from the Eastern Province and C Company was from Kimberley, with many of the men being ex Kimberley Regiment. D Company was recruited from Cape Town. Most of the recruits already had military training or experience. They were, in general, middle class, well-educated and well-bred men.
The regiment was led by serving officers of the Union Defence Force, while the whole of 1st South African Infantry Brigade came under the command of Brigadier-General Henry Lukin DSO, a previous Inspector General of the UDF and part of the South African Overseas Expeditionary ForceThe Brigade was attached to the 9th (Scottish) Division.