The historiography of Hausaland has laboured under a strong tradition of orthodoxy which recent secondary works have inherited from the more-or-less primary oral-cum-written sources. General cultural evidence (linguistic, ethnographic and archaeological) has been regarded as subsidiary, so that its potential for reconceptualization and for critical reevaluation of the conventional sources and orthodox interpretations has been missed. Instead, antiquarian approaches have been encouraged. Thus the view has persisted that Hausa as a cultural and linguistic entity has an antiquity running to several millennia, and also that it originated in the Sahara or around Aïr, whence it was pushed southward by desiccation or by Tuareg nomads. Contrarily, the clear message of linguistic geography and of Hausa's place within the Chadic family is that Hausa. expanded from east to west across the savanna belt of northern Nigeria. And the relative homogeneity of the language and culture within this vast zone indicates that the spread is quite recent (within the present millennium, say). It would have involved some assimilation, of previously settled peoples of the northern Nigerian plains, most of whom wouldl have spoken languages of the ‘Plateau’ division of Greenberg's Benue–Congo subfamily, of Niger-Congo.
This Hausaization, as it proceeded from its old bases in eastern Hausaland, would have been both a cultural and an ecological process, through which woodland would have been converted into more open and continuous savanna to support grain-cultivation and a denser peasant population. This process would have reached western Hausaland (Zamfara and Kebbi) around the middle of this millennium. Cattle – and Fulani herdsmen – would in time have played an important role in this cultural ecology (and in restricting the tsetse zones).
The old theory of a northern origin for the Hausa is bound up with the problem of Gobir in north-western Hausaland. Gobir's claim to be one of the original seven kingdoms (Hausa bakwai) is probably a late invention. Moreover, the common assumption that Gobirawa Hausa migrated from Aïr seems to derive from a misinterpretation of the written sources.
Finally the bakwai legends are reconsidered. Despite the scepticism of some modern critics, the legends appear to reflect, albeit in idealized form, a real historical development. They represent a foundation charter for the Hausa as a multi-state ethnicity, and enshrine the vague memory of how Hausaland and ‘Hausaness’ began from a series of small centres and hill-bases on its eastern side. Thus the interesting argument of Abdullahi Smith, that the Hausa people emerged long before state systems arose among them, is disputed. Rather, these should be seen as two facets of a single process during the present millennium.