Smuts had a large army (for the area), consisting of some 13 000 South Africans, British and Rhodesians, as well as 7 000 Indian and African troops. In addition, he could call on Belgian troops from the Belgian Congo and Portuguese forces from Mozambique. Lettow-Vorbeck had at his disposal just 1 800 Germans and some 12 000 African troops.
“Early in February the 2nd South African Infantry Brigade arrived,” Smuts wrote in his dispatch, “and on the 12th of that month General Tighe directed the 2nd Division to make a reconnaissance in force of Salaita, and if possible to occupy that position. General Malleson carried out this operation with three battalions 2nd South African Brigade and three battalions 1st East African Brigade, supported by 18 guns and howitzers. The Salaita position is one of considerable natural strength, and had been carefully entrenched. The enemy was found to be in force and counterattacked vigorously. General Malleson was compelled to withdraw to Serengeti, but much useful information had been gained, and the South African Infantry had learned some invaluable lessons in bush fighting, and also had opportunity to estimate the fighting qualities of their enemy.
“The original plan devised by General Tighe had been to occupy the Kilimanjaro area by making a converging advance from Longido and Mbuyuni with the 1st and 2nd Divisions respectively, with Kahe as the point towards which movement was to be directed. To this main plan I adhered, but I decided that some alteration of dispositions was necessary in order to avoid frontal attacks against entrenched positions of the enemy in the dense bush and to secure the rapidity of advance which appeared to me essential to the success of the operation in the short time at our disposal before the commencement of the rains …”
This summary by Smuts reflected the approach he took through the entire campaign: the emphasis on mobility and outflanking rather than actual holding of territory.
The plan of campaign called for a main attack from the north, from British East Africa. From the Belgian Congo in the west, two columns of the Force Publique crossed Lake Victoria on board British steamers, while another British contingent crossed Lake Nyasa from the southeast. However, these efforts failed to capture Lettow-Vorbeck. Smuts’s force was severely weakened by disease: one unit, the 9th South African Infantry, found itself reduced to just 116 fit soldiers by October (from 1 135 men in February), having seen virtually no combat.
Lettow-Vorbeck’s tactic was to retreat from the larger British troop concentrations. Smuts was able to gain territory but was unable to put his enemy out of action. By September 1916, the British controlled the German Central Railway from the coast at Dar es Salaam to Ujiji. This meant that Lettow-Vorbeck’s forces were now confined to the southern part of the colony. Smuts, doubtless influenced by the success of the Boers against the British on the vast, dry, open plains of South Africa (and by the more recent and successful campaign in German South West Africa), favoured a tactic of swift manoeuvre. “He was opposed to fighting heavy battles,” wrote Anderson, “and preferred to use limited frontal holding attacks supported by wide turning movements by highly mobile mounted columns aimed at hitting the enemy’s flanks and cutting off his escape … Above all, he wanted to conquer territory and, despite his pronouncements, he never appears to have been really interested in defeating the Germans in pitched battle … His emphasis on speed left little time for accurate reconnaissance.”
This did not mean that Smuts’s army lacked enterprise or courage. In his dispatch, he writes of an attack by Lieutenant Colonel Byron, commanding the 5th South African Infantry:
Shortly afterwards he decided that the best chance of quickly dislodging the enemy from their position on the nek was to send in the two South African Battalions with the bayonet by night. This operation was no doubt fraught with considerable risk as there was no opportunity of adequately reconnoitring the ground over which the attack must be made, nor was it by any means certain that the enemy was not present in large numbers. On the other hand the moon was in the first quarter, and so facilitated movement up to midnight; the bush along the line of the road to the nek did not appear to be very dense; and, moreover, the volume of fire developed by the enemy did not seem to indicate that he had a large force actually in his first line, though he had, as usual, a large proportion of machine guns in action … They advanced with great dash through the bush – which proved to be much thicker than anticipated – driving the enemy before them till the latter was on the crest, where he checked our advance. A certain amount of disintegration was inevitable in a night advance through the dense thorn bush in the face of stubborn opposition.
The map of the campaign seemed to indicate that Smuts had been very successful. He had captured much ground, the ports and railways, and large areas of good farmland. When Smuts left the East African theatre in the spring of 1917 to join the Imperial War Cabinet in London, his successor, Brigadier General Jacob van Deventer, commanding the 1st South African Mounted Brigade, continued to chase the Germans. In July 1917 he launched a major offensive, which pushed the Germans 160km to the south. However, they were still able to tie down large British forces and even defeat them on occasion. Over time, the composition of the British force was steadily transformed, with African troops of the King’s African Riflesbeing brought in to replace South African, Rhodesian and Indian formations. By the end of the war, the force opposing Lettow-Vorbeck was almost entirely African.
In mid-October 1917, Lettow-Vorbeck fought a pivotal and costly battle at Mahiwa, where he lost 519 men killed, wounded or missing. The British Nigerian brigade lost 2 700 killed, wounded or missing in the engagement. Smuts was to write of Van Deventer that he “commanded throughout the operations an independent column, and executed the turning movements to which the rapidity of our success was undoubtedly due. He displayed soldierly qualities of a high order in controlling the mounted troops in their long night marches and manoeuvres through unknown and extremely difficult country.”
However, Lettow-Vorbeck remained undefeated. For the next year, he sustained an amazing campaign of evasion and delaying tactics. In November 1917 he crossed into Portuguese East Africa (Mozambique) to gain supplies by capturing Portuguese garrisons, and with his caravans of troops, bearers, wives and children, he marched through Mozambique for the next nine months. In August 1918 he moved back into German East Africa and then Northern Rhodesia. On 13 November 1918, two days after the Armistice was signed in France, the German army occupied its last town, Kasama, which had been evacuated by the British. The next day, at the Zambezi River, Lettow-Vorbeck was handed a telegram announcing the signing of the armistice and he agreed to a ceasefire. He surrendered his undefeated army on 23 November 1918.
Ross Anderson summed up the different personalities and styles of the two South African commanders-in-chief:
If the standard of military success is victory on the battlefield then it is difficult to judge Smuts a success. While he captured a great deal of territory, he never seriously threatened the existence of his enemy and left the theatre with their morale and fighting power unharmed. On the debit side, he had to evacuate the bulk of his army through ill health and those who were left were in no condition to carry on the advance.
Van Deventer was given the mission of ending the campaign as rapidly as possible. In this he failed, as Lettow-Vorbeck did not surrender until after the signing of the Armistice. However, he achieved a number of successes in the field, reducing his opponents to little more than a band of weakened companies and enabling the withdrawal of a large number of his own units. His policy of attacking the enemy's food supplies was a sound one and hastened the end of resistance in German East Africa. Van Deventer also occupied a considerable amount of enemy territory … and maintained a mobile and hard-hitting force until the end of the war. In the final analysis, although Smuts was well known and lauded for his exploits, Van Deventer must be considered the better general.
Early German armoured cars in the South West Africa campaign.