On the advice of his wartime commander, Jan Smuts, he returned to South Africa in 1906. The malaria he had contracted in Madagascar had so severely affected his health that he collapsed unconscious upon his return to South Africa. He was nursed back to health over three years by Jan Smuts' wife, Isie. He then completed his studies and in 1908 in Heilbron began his successful career as a lawyer. In 1914 he helped Smuts suppress the Maritz Rebellion in the Free State, and he served on Smuts' army staff in the "German West campaign" (in the German colony of South-West Africa) and in the "German East campaign" (in German East Africa) where he rose to command a mounted regiment. On the Western Front during World War I he commanded the First Battalion, Royal Scots Fusiliers in 1918, after being wounded in late 1917 while serving with 6/7th Battalion Royal Scots Fusiliers. He led his men to the Rhine after the Armistice, as detailed in his book 'Trekking On'.