Commanding a force of roughly 40,000 South African and Indian soldiers, Smuts' offensives pushed Von Lettow-Vorbeck and 4,000 men into a slow and determined fighting withdrawal southward towards the interior of the colony.

Although offensives along the coastline had been significantly more successful, with the key port of Dar es Salaam falling by the end of September 1916, military operations for the interior became increasingly frustrated and hindered by disease.

In an environment where vehicles were of limited use, between June and September over 53,000 draught animals had died from illness, with most South African units losing half their number to disease and poor nutrition.

Smuts, with the campaign stalling around the Rufigi River, left his East African Command after being asked to join the Imperial War Cabinet in London.

Although Smuts' offensives had been successful, securing three-quarters of German East African territory and its entire infrastructure, Von Lettow-Vorbeck and his small force refused to surrender and continued to engage in a strategy that drew disproportionate amounts of Allied resources away from Europe.

Although Van Deventer lost more men, Von Lettow-Vorbeck faced a far more serious situation as he could afford the casualties and had to abandon already dwindling ammunition, supplies and field guns.

After Van Deventer moved into Mozambique in pursuit in July 1918, Von Lettow-Vorbeck skilfully outmanoeuvred the South African and returned to German East Africa to conduct supply raids on the lightly defended Northern Rhodesia border.

Two weeks after the armistice signed in Europe, on 25 November 1918 Von Lettow-Vorbeck finally surrendered at Abercorn near Lake Tanganyika after evading capture for over four years.

After the recapture of the final settlement of Sallum on the Libyan – Egyptian border on 14 March 1916, the brigade was then transferred back to the Western Front as part of the 9th (Scottish) Division.

From April 1916 until the war in Europe ended on 11 November 1918, South Africa fought alongside other Allied nations at battles of the Somme in 1916; Arras, Ypres, and Menin in 1917; and Passchendaele, Messines, Mont Kemmel, and Cambrai in 1918.

Attached to the British 9th (Scottish) Division, the South African 1st Infantry Brigade was deployed to France in mid-April 1916 in anticipation of the upcoming Somme Offensive.

As the Somme Offensive declined into a war of attrition with enormous casualties on both sides, the Brigade was ordered to capture Delville Wood, just to the east of Longueval, on 14 July and hold it at all costs.

At dawn the following day, the 3,000 South African soldiers led by Lieutenant Colonel William Tanner successfully captured most of the wood and started to prepare defensive positions.

Suffering constant artillery fire and an eventual two-thirds casualty rate, South Africa won great respect for their courage and holding their objective.

As the war entered its final year, in early 1918 the Brigade was tasked with holding a defensive position at Gouzeaucourt, near Cambrai, in anticipation of the German spring offensive.

From October 1916, the first continents of the South African Native Labour Corps (SANLC) began arriving in France under the command of Colonel S.A.M Pitchard.

Employed in French dockyards, railways, quarries and logging camps, the Native Labour Corps often won great praise, even from the Commander in Chief of the British Army Douglas Haigh, for their vital contributions to the war effort.

The white officers and NCO rigorously enforced racial segregation during their time in France, minimising European and African contact by operating closed compounds.

Transporting 823 men of the Native Labour Corps, 616 South Africans were killed when the cargo ship SS Darro pierced Mendi's starboard quarter when travelling at dangerously high speed through the English Channel.

The SA Field Artillery and the Cape Corps fought in British operations against Turkish forces in Palestine from August 1917 until the end of the war in November 1918.

Assigned to the Egyptian Expeditionary Force (EEF) under General Sir Edmund Allenby, the Corps was originally designated light duties behind the lines, such as a prisoner of war escort, due to South African racial policies.

By the end of June, the Corps had joined the British and Indian 160th Brigade that had deployed forward positions north of Jerusalem and alongside the Jordan River.

In late September, the Cape Corps advanced against Turkish positions northeast of Jerusalem that had become slightly weakened due to disease, desertion, and the effects of Allied artillery.

Many returned to jobs that had been reserved by their employers, whilst others joined the Allied Expeditionary Force in Russia that was fighting the Bolsheviks, and some became part of the radical mineworkers' movement that led the Rand Rebellion in 1922.