One of the main problems of the cultural and linguistical history of Africa is linked to the phenomenon of the peopling of most of southern Africa by Bantu-speaking peoples. The spread of the over 600 Bantu languages (Nurse & Tucker 2002) from a hypothetical "nucleus" in northwestern Central Africa, namely the borderland of Nigeria and Cameroon, over almost all of southern Africa, is explained by spacious movements of the populations of Bantu speakers (Eggert 1981).

Therefore the equatorial rainforest is of pivotal significance, since it is essentially settled by Bantu speakers. It is further of mayor importance for the spread of the Bantu languages throughout subequatorial Africa. In his dissertation Hans-Peter Wotzka (1995) pleaded for a hypothesis which links the settlement of the rainforest to the intrusion of ceramic producing populations into Hyläa.

We would like to contribute as fundamentally as possible to clarify when, under which ecological circumstances, with which material culture and on which susistancial basis the settlement of the rainforest by ceramic producing populations had been possible. It needs no further emphasis that the results gained by these investigations are of paradigmatic interest for the settling of the equatorial rainforest of southern Cameroon and beyond.

As early as 1997 the department of the Tübingen university, supported by the German Research Foundation, effected archaeological fieldwork in Cameroon. Then, the focus was on the acquistion of local and regional ceramic sequences. The chronological order of the ceramic-yielding layers (and therefore the ceramics within those) is deduced by dating organical residues. These involve mainly charcoal, bones, fruit kernels and other substances, whose age can be determined by 14C-dating.

The different structures ("features" in archaeological terms) which contain these residues, are often over 2 m deep pits. These have been used then by people as either garbage disposals or for ritual functions. The features are excavated, documented and analysed by the archaeologists. The main difficulty is to locate them in the rainforest, since the thick vegetation (Fig. 2) conceals every trace of settling activity of past times - which can only be discovered by dark discolorations in the soil (Fig. 3).

Since the distribution of the rainforest has changed throughout the millennia, we are going to examine in how far the settling activities are linked to climatic-vegetational factors. Therefore a collaboration with archaeobotanical and geographical researchers is of pivotal importance. Building on geomorphological analyses, archaeobotanists try to detect localities, mainly lakes and rivers, where pollen is preserved (Fig. 4). These pollen archives can be used to reconstruct a past vegetation. In the remit of archaeobotany lies also the
analysis of larger botanical residues, such as charcoal. The results are also used to reconstruct a former environment. Then again the geomorphologists are trying to explain the formation of important environmental facts, such as the alteration of the landscape by meandering rivers, erosion and sedimention processes.

To sum up, it is only possible to provide an adequate picture of the interrelationships between biophysical environment and cultural conducts, by an intimate interdisciplinary collaboration of archaeology, archaeobotany and geography. The equatorial rainforest is inasmuch of central interest, as it is, alike most of Southern Africa, settled by Bantu speakers (Fig. 5). If we bear in mind that the "Urheimat" of those approximately 600 closely related languages is suspected in the borderland between Cameroon and Nigeria, the cultural-historical impact of the here discussed research will be undoubtedly evident.

The archaeological group of the central african part of the project is lead by
Prof. Manfred K. H. Eggert of the Institut of Pre- and Protohistory and Medieval archaeology, whereas the archaeobotany is headed by PD Katharina Neumann of the Abteilung Archäologie und Archäobotanik Afrikas des Frankfurter Archäologischen Institutes. The Geography is lead by Prof. Jürgen Runge of the Institut für Physische Geographie in Frankfurt. The research group collaborates closely with the Direction du Patrimoine Culturel du Ministère de la Culture (Dr. Christophe Mbida) and the Département de l’Art et d’Archéologie of the Université de Yaoundé I lead by Dr. Martin Elouga.

The project takes up on the results of River Reconnaissance Project headed by M. K. H. Eggert within 1977 to 1987 in the Congo. Then the archaeologists also investigated the origins of settlement of the central african rainforest. In 1997 Eggert initiated yet another project where he had left off in 1987 with a survey, this time in Cameroon. A trip of about 800 km was mainly used for prospecting the roads between Yaoundé and Abong-Mbang, Bertoua, Batouri and Yokadouma in the Southeast of Cameroon. A second journey in 1998 was restricted to the environs of the lower Sanaga river near Edéa. The wintermonths of 1998 and the spring of 1999 (dry season in Cameroon) were spent there to excavate the pit complexes of Lobethal and Yatou.

With the establishment of the research group in 2004 the archaeological activities commenced again between November 2004 and March 2005, January 2006 and March 2006 as well as January 2007 and April 2007. The archaeological fieldwork was preceded by reconnaissance of the respective regions in the spring of 2004, 2005 and 2007. Here, we profited greatly from the help and knowledge of our cooporating cameroonian colleagues. Road- and river banks, which had been exposed by roadworks or erosion, as well as surfaces without vegetation, were of central interest and therefore inspected.