The campaign, led by Boer War hero Louis Botha, to reduce the German colony (now Namibia) was a South African-only operation which saw the birth of the South African Air Force and was successfully concluded in July 1915. This is the Official South African History of The Great War, describing a campaign in which South African forces only were involved, hence it does not feature in the British Official History series. It was the first occasion of the employment on active service of the then recently formed Union Defence Forces, which had come into being under the South Africa Defence Act of 1912. It saw the birth of the South African Air Force and the first use on the continent of Africa of aircraft in a bombing role, which consisted of heaving shells over the side of the cockpit and hoping they would land nose down and thus explode. The South African commander was Gen. Louis Botha, the distinguished Boer War leader who, having first to deal with a pro-German Boer rebellion which verged on civil war, fought a brilliant campaign and, in July 1915, German South West Africa (today's Namibia) surrendered.