A British Crown Colony established over the former South African Republic (Transvaal/ZAR) territory - with somewhat larger borders than the defeated Boer republic - following the Treaty of Vereeniging that ended the Second Boer War.
Became the Transvaal Province of the Union of South Africa on 31 May 1910.
Contemporary account specifically about British reconstruction administration of the two 'New Colonies' - Transvaal and Orange River - in exactly this 1902-1910 window.