The result was disappointing in the escape of the German cruisers, but it left no doubt about the command of the sea. It was, indeed, being daily demonstrated by the security of the Channel passage, the muster of forces from oversea, and the conquest of German colonies. These were mainly in Africa, and consisted of Togoland, the German Cameroons, German South-West Africa, and East Africa. The tide of conquest flowed in this order round Africa from north-west to south-east, and Togoland, which was also the smallest, was the first to be subdued. It was about the size of Ireland, and was hemmed in on all sides, by British sea-power on the south, Nigeria on the west, and French colonies on the north and east; and converging attacks forced the handful of German troops to unconditional surrender on 27 August, The Cameroons were larger than the German Empire in Europe, and the first attacks, being made with inadequate preparation, were repulsed in the latter days of August. On 27 September, however, by co-operation between French troops and two British warships, Duala the capital was captured and the whole coast-line was seized.
The conquest of German South-West Africa was a more serious matter, not only because the Germans were there more numerous and better organized, but because the task was complicated by the politics of the Union. It was not a Crown colony subject to the orders of the Imperial Government; troops could only move at the instance of a responsible local administration, and the back-veld Boers, led by Hertzog and De Wet, were strenuously opposed to participation in the war on the British side. Fortunately, perhaps, the Germans began hostilities by raiding the frontiers of Cape Colony, and on 18 September the British retaliated by seizing Luderitz Bay, which, like their other port, Swakopmund, the Germans had abandoned to concentrate at their inland capital, Windhoek. On the 26th there was a small British reverse at Sandfontein, which was followed by the more serious news of Maritz' rebellion in the Cape. Maritz had fought against the British in the Boer War and for the Germans against the revolted Hereros; he now held the ambiguous position of rank in the German Army and command of British forces, but came down on the German side of the fence. Botha ordered his arrest, and Maritz, with German assistance in arms and ammunition, attempted to overrun the north-west of Cape Colony. A fortnight's campaign in October ended with the dispersal of his commandos by Colonel Van Deventer.
Maritz was the stormy petrel of a far more serious disturbance. While the grant of self-government to the Transvaal and the Orange River Colony in 1908 had placated the great majority and the better-educated Boers, tradition and prejudice kept their hold upon the more conservative minority; and some like Beyers, who had once been received by the Kaiser, looked to a war with Germany to restore their ancient independence. On 24 October De Wet seized Heilbronn in the Orange State, and Beyers Rustenburg in the Transvaal. Botha's appeal to the loyal Boers met, however, with an effective response, and soon he had 30,000 men at his disposal. He acted with remarkable swiftness: on the 27th he dispersed the commandos of Beyers and Kemp, and on 7 November General Smuts announced that there were but a few scattered bands of rebels in the Transvaal. De Wet made a longer run by his elusive heels, but found the motor-transport of his enemies an insuperable bar to the repetition of his exploits of 1900-2. He had a slight success at Doornberg on 7 November, when his force amounted to 2000 men; but Botha now came south into the Orange State and completely defeated De Wet on the 11th to the east of Winburg. De Wet himself escaped and attempted a junction with Beyers who had fled south from the Transvaal. But he was gradually driven westward into the Kalahari desert and overtaken by Colonel Jordaan's motors a hundred miles west of Mafeking on 1 December, while Beyers was drowned in trying to cross the Vaal on the 8th. De Wet was once more given his life, and the other rebels were treated with a lenience which nothing but its wisdom could excuse.
The rising put off to another year the conquest of German South-West Africa. The conquest of East Africa (see Map, p. 249) was postponed for a longer period by the inherent difficulties of the task and the imported defects in its management. German East Africa was actually and potentially by far the most valuable of German oversea possessions. Twice the size of Germany, it had a population of eight million natives and five thousand Europeans. Although tropical in its climate, high ground, and especially the slopes of Kilimanjaro, provided inhabitable land for white men, and its wealth in forests, gold and other minerals, pastoral and agricultural facilities was considerable. There were four excellent ports, and from two of them, Tanga and the capital, Dar-es-Salaam, railways ran far into the interior. On the north it was bounded by British East Africa and Uganda, on the west by the Belgian Congo State, and on the south-west by British Nyasaland and Northern Rhodesia, while on the south Portuguese Mozambique provided some means of supply and an ultimate refuge in defeat. The German forces were greatly superior to those of the British in East Africa, and the Uganda railway from Mombasa to Lake Victoria Nyanza running parallel with the frontier was a tempting object of attack. The Germans took the offensive against the British north and south-west, without achieving any great success. But only the arrival of reinforcements from India on 3 September and the failure of the Konigsberg to co-operate prevented the fall of Mombasa, and only the inadequacy of the British maps, on which the Germans had for once to rely, frustrated their attack on the Uganda railway. Karungu was also besieged on Lake Victoria Nyanza, but relieved by a couple of British vessels; the invaders of Northern Rhodesia were beaten back; and a naval force bombarded Dar-es-Salaam and destroyed the wireless installation. The arrival of a second expeditionary force from India on 1 November was the prelude to a greater reverse. Landing at Tanga on the 4th, it was met by a German force, superior in the art of bush fighting if not in numbers which hurried down from Moschi, and was compelled to re-embark with a loss of 800 casualties. During the brief span of their colonial experience the Germans had learnt as much about colonial warfare as we could teach them after centuries; for traditions are not an unmixed blessing in the art of war.