Many observers of Merina history have suggested that the organization of labour required to build and maintain irrigation works for paddy rice growing formed the basis of Merina monarchy. Though little direct evidence is available, inferences from land-use models and consideration of oral traditions and written accounts help to explain why irrigated riziculture became popular and how it spread through the central highlands to Imerina.

Rice had been cultivated on the east coast of Madagascar for centuries and reached Imerina through the southern plateau but the hydraulic technology of Merina paddy rice growing arose from local needs from the late seventeenth to mid-eighteenth centuries. As swidden farmers exhausted the forests, paddy rice cultivation and water management systems attending it became increasingly important. Though irrigated riziculture enhanced the value of co-operative labour among hitherto isolated groups within Imerina, it cannot be seen as the direct cause of the monarchy's authority. It is suggested instead that the sacredness of land and the accumulation of rights in newly irrigated land by those who controlled water hastened the evolution of a rigid social hierarchy which exalted a few and subjugated the rest.

This essay questions the generally held view that the northern Nguni were not involved in the slave trade. It is shown that elements of the Ngwane (Swazi), Ndwandwe (Gaza and Jere) and possibly Mthethwa (Zulu) confederations were involved in the sale of slaves captured in the hinterlands of Lourenço Marques and Inhambane. In the 1840s the terms of the slave trade turned against suppliers as British and anti-slavery activities caused a rise in slavers' overheads, a surfeit of saleable slaves on the coast and a consequent price drop. The export of slaves through Lourenço Marques and Inhambane became unprofitable as the two trading posts were unable to compete with the safer embarkation points north of the Zambezi. As the export of slaves from the coastal settlements south of the Zambezi declined, the trade from this area took on a new form as engagé labour for the Indian Ocean islands and as non-contracted and unprotected ‘migrant’ labour for Natal and Kimberley. Slave suppliers ceased to sell slaves for export through Lourenço Marques and Inhambane because far higher prices could be obtained from Transvaal Boers and from domestic purchasers. But it was the rise of domestic slavery in the Gaza state that finally ended the maritime export of slaves as by the 1860s, with the loss of labour through warfare and increasingly through migrant labour, it was more profitable to use slaves locally than to export them.

Domestic slavery in the Gaza state is treated as a dynamic social relationship in which the slave, as against the kinsman, had no rights and was consequently entirely dependent upon his master for his means of production and reproduction. It was this dependence which resulted in the extreme exploitation defined here as slavery. Slavery should not be seen merely in a functionalist sense as a form of socio-political incorporation aimed at expanding the size of the ruling group. In a society controlled by kinship rights and obligations, slavery provided a man with a means of accumulating wealth and attracting followers. Thus slave labour was realized in the form of repatriated wages; female children born of concubines provided their fathers with brideprices while male children had limited kinship rights and were therefore more exploitable than ‘legal’ offspring. Slave labour also released Gaza Nguni women from agricultural work and allowed them to concentrate on the child-producing and child-raising activities that ensured a putative Gaza Nguni ‘purity’ and, consequently, the perpetuation of the exploitative structure of Gaza society.

In a society that had no concept of ‘free’ labour, i.e. labour freed from its former means and relations of production, the distinction between slave and non-slave labour was often blurred, and a disadvantaged kinsman could hypothetically be materially worse off than a slave. Zulu and Swazi forms of servility are examined and are shown to have been only marginally different from Gaza slavery. From this it is deduced that Gaza slavery had its roots in the relations of production taken northwards from the Nguni area. Slavery is seen as a new and more exploitative social relationship that arose in response to the emergence of new forms of production in southern Mozambique.

The utilization of a relatively unused source, the Customs Bills of Entry, enables the structure of the British side of the West African palm oil trade to be studied in detail. Three main developments emerged in the period from 1830 to 1855 when the introduction of regular steamer services radically altered the trade. Firstly, Liverpool's pre-eminence as the main British palm oil port began to be challenged by Bristol and London; secondly, Britain's reliance on the Niger Delta as a source of supply appears to have proportionately declined, and thirdly, new traders entered the trade, especially after 1840, and challenged the hegemony of the older, established merchants. These structural changes suggest that the organization of the British side of the oil trade, hitherto controlled by a few large Liverpool traders, was breaking down from the 1840s and that this contributed to increased tension and rivalry among British traders in West Africa. This in turn helps to explain the development of the aggressive behaviour between British traders and African middlemen, noted in the Niger Delta in the 1860s, which led to the subsequent appeals for British imperial intervention.

In Angola, climatic instability contributed to maintaining a precarious balance between food resources, population and disease long before the nineteenth century. Periods of exceptionally irregular rainfall, lasting several years, were preceded or accompanied by plagues of locusts which caused famines at least once every decade. The coastal lowland and the extreme south were especially vulnerable. Prolonged hunger crises led to malnutrition, lowered resistance to disease and epidemic outbreaks, especially of smallpox. A rhythm of drought and smallpox can be discerned in Angola, at least since the seventeeth century. From the 1830s the gradual decline of the overseas slave trade and rise of commerce in raw materials and cash crops brought important demographic changes. These contributed to the worsening famines and epidemic crises of the late nineteenth century. Commercial instability and rural depopulation hindered the growth of Portuguese plantation prosperity. Soon after, however, similar crises aided Portuguese military conquest in Angola by weakening African ability to mobilize effective resistance. In the twentieth century malnutrition continued to be the most widespread problem of Angola's Africans and on occasion it drove them to revolt.

A. G. Hopkins has observed that where new plants and seeds were adopted it was because they were seen as useful additions to the existing range of foods, or because they were regarded as good substitutes to the crops they displaced. This view is confirmed by a close study of the changing food patterns on the Lower Niger since 1520. Prior to 1919, cassava was hardly cultivated on the Lower Niger even though it was widely grown in the neighbouring Niger Delta. This was essentially because the people of the Lower Niger did not consider cassava as a good substitute for yams. However, after 1900 the Lower Niger became the scene of wars of resistance against the imposition of British rule. These wars not only resulted in a constant disruption of the agricultural activities of the local people, they also caused food shortages. The situation was worsened by the First World War and by the pandemic of influenza of 1918–19 which drained the nation's productive capacity and caused an unprecedented food scarcity. Under the circumstances, the people of the Lower Niger were constrained to accept cassava, at least as a supplement to the dwindling stocks of food. And as soon as it was realized that the new crop enjoyed a number of advantages over yams, its cultivation rapidly spread to all parts of the Lower Niger where it began to threaten the older staples. The speed with which this innovation was adapted clearly points to the degree of the food crisis that accompanied the pandemic influenza of 1918–19.

La décolonisation de l'Afrique Equatoriale Française présente cette particularité que l'initiative en venue des pouvoirs coloniaux, métropolitains et locaux, qui ont su contrôler de bout en bout le mouvement d'émancipation politique. Ce n'est pas que les Africains aient subi passivement cette évolution. L'analyse des forces sociales montre deux groupes n'ont pas étée en mesure d'intervenir efficacement et durablement sur la scène politique: l'une, la chefferie, apparaît comme une force déclinante dans la conjoncture 1940–1960, ruinée à la fois par l'éevolution économique, les transferts de revenus au sein de la population africaine, l'affirmation de valeurs nouvelles; l'autre, la masse ouvrière, était trop émietté, en termes de localisation et d'organisation, pour mener une action autonome. Ce fut done à la classe montante, la petite-bourgeoisie, qu'échut le rôle politique moteur du côté africain: mais, dans les conditions particulières de l'A.E.F., cette classe ne fut pas capable, ni peut-être désireuse, d'élaborer une idéologic et des pratiques anti-impérialistes ou même seulement anti-colonialistes.