Crabbe led his battalion to Pretoria and on to the border with Portuguese East Africa at Koomati Poort but their hopes of returning to England with Field Marshal Lord Roberts in November 1900 were dashed.
In November 1902 Crabbe became Assistant Quartermaster General (AGMG) of 1st Army Corps at Aldershot, and in May 1903 Chief Staff Officer of 4th Army Corps also at Aldershot.