The Igbo-speaking area in southeastern Nigeria extends between 4[H11034]55[H11032]–7[H11034]05[H11032] N and 6[H11034]30[H11032]–7[H11034]45[H11032] E. As elsewhere in West Africa, the levels of rainfall and humidity decrease with distance from the coast, with a rainy season between April and October. Most of Igboland is situated within the oil palm belt, bordering on the coastal mangrove swamp in the south and the savanna in the north. The River Niger formed the western boundary of the colonial Eastern Region that included the major part of Igboland; in addition, a number of Igbo-speaking communities are found west of the river. In the east, Igbo communities extend close to, and some of them (Unwana, parts of Afikpo) reach, the Cross River (for geographic information, see Floyd 1969; Ofomata 1975, 2002).

For centuries, southeastern Nigerian agriculture was based on yam as the most important source of carbohydrates, the crop's importance being expressed in the rituals and honorary titles that many Igbo communities devote to it. Cassava, introduced from South America to West Africa in the seventeenth century, seems to have spread slowly and reached its current prominence only during the twentieth century; the production of rice started only in the 1940s. Besides these staple foods, numerous vegetables and fruits are grown. Oil and raffia palms are the most important “economic trees,” providing the source of vegetable oil (for domestic use and as a cash crop) and palm wine, respectively. For communities in the “riverine” areas (close to the Niger and its delta), fishing is major source of livelihood. Due to the prevalence of trypanosomiasis, animal husbandry has been limited to the keeping of small stock.

Igboland includes some of the most densely settled areas in Africa. While there is considerable variation within the region, the 1963 census noted very high population densities of 400–600 persons per square kilometer in the Awka, Okigwe, and Orlu areas (Okorafo 2002: 140). Igbo farmers expanded over centuries through the area. But except in the frontier zones on the Cross River and in the northeast, where space for territorial expansion appears to have been available until more recently (see Jones 1949b), much of the population growth took place in areas where “internal colonization” was the only option. Today, soils in many areas are exhausted, and problems of erosion are widespread.