During the 1920s, South African authorities expanded surveillance over movement between Ovambo and the Police Zone. The creation of the Southern Labour Organisation and Northern Labour Organisation in 1925 reorganised recruitment: the former supplied labour to South African-owned diamond mines, while the latter recruited for the German-owned copper mine at Tsumeb and for white farms. Administrative interest was strongest in Ovambo because its population represented a major potential labour reserve, whereas Kaoko, Kavango and Caprivi received more uneven and limited attention.

The depression and the failure of rains in eastern Ovambo in 1928 gave the administration new opportunities to increase its influence. Road-building and other projects were established for male Ovambo labourers in the Police Zone, while food-for-work schemes were organised in Ovambo itself. Dams were first built at Ondonga in August 1929, and later projects extended into other areas as famine spread. Although these measures provided some relief, they also compelled able-bodied men into contract work and brought many women into direct contact with the colonial state through labour on public works.

The famine also affected Kaoko, where isolation and restricted trade made access to food increasingly difficult. In 1929–31, approximately 1,200 people were removed from southern Kaoko to its centre, an episode described as one of the major forced removals in Namibia’s colonial history. In Ovamboland, the state declared a reserve and introduced a head tax on Ovambo men, payable in grain or cash. These policies connected subsistence communities more tightly to colonial labour and taxation while limiting their room for economic autonomy.

Colonial intervention became more forceful in the 1930s. In early 1932, Lipumbu, king of Uukwambi, resisted a colonial fine and attacked a Finnish mission station to recover one of his subjects. After he refused to pay the imposed fine, South African forces destroyed his palace by aerial bombing, prompting his flight to Kavango. The episode allowed the administration to impose councils of headmen on Uukwambi and other Ovambo polities, while Hahn worked to promote younger rulers and reduce the military capacity of the kingdoms.

The colonial state also intervened more directly in Kaoko and Kavango. In 1935, after a case involving murder and elephant-killing, the administration imprisoned Vita ’Tom, a Himba leader, and Thomas Mutate, ending a long alliance with them. Hahn replaced Tom with a council that included seven Herero members and expanded the Kaokoland Tribal Council. In Kavango, Rundu became the Native Commissioner’s residence in 1936, while police posts and roads strengthened administrative control. Caprivi, transferred to Windhoek’s control in 1929, received further policing and infrastructure, including a road linking the Kwando River to Katima Mulilo and Schuckmannsburg in 1930.

These interventions were accompanied by political and economic regulation. Adult-men taxation was introduced in 1930, firearm registration followed in 1931, and the Caprivi was placed under direct South African control in 1939. In the eastern reserves, leaders such as Hosea Kutako combined limited cooperation with vocal criticism of South African rule. Urban controls also intensified: the state restricted African women’s entry into towns, removed some people to reserves, policed illegal beer-brewing and introduced compulsory examinations for venereal disease in 1939.

Missionary activity contributed to major social changes in Ovambo from about 1920 onward. By 1951, the region had approximately 71,000 Christians among a total population of 198,000, including Lutheran, Catholic and Anglican converts. Christianity attracted many poorer commoners, for whom conversion could provide new forms of freedom or protection, while some members of the political elite also adopted the religion. Uukwaluudhi, however, did not have a Christian king until 1961.

Missionaries opposed aspects of Ovambo culture including dress, ritual and bridewealth, and female initiation and bridewealth became sites of conflict during the 1930s. The administration generally offered limited support to missionary campaigns because it wanted Ovambo to remain a stable base for migrant labour. Officials instead promoted a rigid version of ‘tradition’, emphasising women’s productive and reproductive roles and restricting their migration. The text links this policy to the erosion of women’s land rights and to the marginalisation of divorced wives.

Economic recovery after 1933 transformed the balance between farming, mining and migrant labour. White-owned agriculture expanded, especially through karakul farming, while mining did not recover its earlier share of the economy until after the Second World War. Contract labour recruitment from the north rose sharply between 1937 and 1940, although workers retained some capacity to resist, as shown by protests that forced Consolidated Diamond Mining to stop recruiting in Ovambo in 1938. In 1943, the Southern Labour Organisation and Northern Labour Organisation merged into the South West Africa Native Labour Association, which controlled contract workers employed in the Police Zone.

Interwar colonial rule also relied on the production of ethnographic categories. Earlier European and missionary descriptions had assigned Africans to supposedly primordial and unchanging ‘tribes’, while missionary organisation often followed ethnic lines. The text presents these classifications as inventions that obscured fluid and changing histories. In the interwar period, such ideas continued to shape colonial policy and public understandings of African societies.

Heinrich Vedder’s The Native Tribes of South West Africa (1928) and Das Alte Südwestafrika (1934) contributed to this body of knowledge. The former treated Ovambo, Herero, Nama, Damara and Bushmen as Namibia’s principal ‘tribes’, while the latter represented precolonial history as a long sequence of conflicts from which German rule alone could provide liberation. These formulations reinforced assumptions of African inferiority within contemporary Social Darwinist thinking.

The classification of Africans also had consequences for gender and urban policy. Authorities treated African women as potential disruptors of the social order, especially where urbanisation and wage work challenged settler expectations. Efforts to confine women to ‘traditional’ roles therefore formed part of a broader programme of social control, racial ordering and labour management. The same framework helped sustain white rule by presenting African societies as fixed, hierarchical and in need of external administration.