The documents in Part III record the Anglo-Boer War as Smuts experienced it. They fall into four groups as follows:

1. (a) Papers on the period from the beginning of the war until the fall of Pretoria on 5 June 1900.

2. (b) Papers on the operations in the Western Transvaal (July 1900–May 1901).

3. (c) Papers on the abortive peace negotiations and the Waterval Conference (May–June 1901).

4. (d) Papers on the invasion of the Cape Colony (August 1901–April 1902).

(a) The first document in this group (130) is dated more than a month before the war actually began. It is a remarkable memorandum by Smuts on military and diplomatic strategy in the war which he already believed to be imminent. Smuts held no military command during the first phase of the war. It has not been possible to find documents that show what part he played in the war organization of the South African Republic while its forces were invading Natal and attacking Kimberley, Mafeking and the key points of the railways to the Cape ports, though it is clear that he paid visits to the Natal front. Nor is there much record of his activities during the early months of 1900 when the British forces drove the Boers out of the Colonies and moved strongly into the Republics. One confident letter of these months survives (132)—to Louis Botha; it is the earliest extant record of their association.