The Supreme Court of Mauritania (Cour Suprême de Mauritanie), sitting in cassation over a judgment of the Court of Appeal of Trarza, delivered a landmark ruling on the relationship between the formal land-register system established by the 2023 Land Code (القانون رقم 2023-013 المتعلق بنظام الأراضي) and the customary land holdings of agricultural communities in the Senegal River valley. The dispute concerned a tract of irrigated rice land near Rosso that had been farmed by the respondents' family under continuous, public, and peaceful customary occupation since the 1970s, without any formal registration. In 2022, the claimants acquired a registered title (titre foncier) to the same parcel from the state, which had classified it as unallocated domain land in the course of a cadastral update. The claimants sued for eviction. The Supreme Court held that (i) customary occupants of agricultural land who have held the land continuously, publicly, and peacefully for more than ten years acquire a real property right (droit réel) that is opposable to subsequent registered title holders; (ii) the 2023 Land Code's general requirement that all real rights over immovable property be registered does not, of itself, extinguish unregistered customary rights that pre-date the registration and that the registered title holder knew or ought to have known about; and (iii) the burden of inquiring into the existence of such customary rights at the time of acquisition falls on the purchaser of registered title. The decision is the leading Mauritanian authority on the coexistence of statutory registration and customary tenure, and it provides important guidance for the resolution of land disputes arising from the ongoing national cadastral programme.
Mauritania's land law is rooted in a French-civil-law tradition that has historically recognised only registered title as creating opposable real rights over immovable property, while in practice a substantial share of agricultural land in the Senegal River valley, in the Hodh regions, and along the Adrar has been continuously held under customary tenure by communities that have never formalised their occupation through registration. The 2023 Land Code, intended to rationalise the land regime and to support the national cadastral programme, affirmed the principle that registration is the formal mode of constitution of real rights, but included transitional provisions intended to protect established occupants. The dispute arose in 2022, when the claimants, a Nouakchott-based investor, acquired a registered title to a 12-hectare parcel of irrigated rice land on the west bank of the Senegal River near Rosso, in the wilaya of Trarza. The state's concession had classified the land as unallocated domain land (domaine non affecté) following a cadastral update, although the parcel had in fact been continuously farmed by the respondents' family as part of a village collective holding since the 1970s. The respondents refused to vacate, asserting a customary land right that they traced to allocation by the village chief and continuous cultivation by successive generations. The claimants sued for eviction in the Tribunal de la Wilaya of Trarza; the tribunal found for the claimants on the ground that the registered title was, by force of the 2023 Land Code, conclusive against unregistered occupants. The Court of Appeal of Trarza reversed, holding that the respondents' long customary occupation had given them a real right that the registered title could not defeat. The claimants appealed in cassation to the Supreme Court.
The Supreme Court framed three questions for determination: (1) Whether customary occupation of agricultural land, continued peaceably, publicly, and without interruption for a period of more than ten years, gives rise to a real property right that is opposable to a subsequent holder of registered title; (2) Whether the 2023 Land Code's general requirement that all real rights over immovable property be registered has the effect of extinguishing unregistered customary rights that pre-date the registration, where the registered title holder knew or ought to have known of the customary occupation; and (3) Upon which party the burden of inquiring into the existence of unregistered customary rights at the time of acquisition of registered title falls.
The Supreme Court dismissed the claimants' appeal and affirmed the judgment of the Court of Appeal, issuing the following holdings:
(1) Customary occupation of agricultural land for more than ten years gives rise to an opposable real property right. The Court held that, although the Mauritanian legal system has historically recognised only registered title as the formal mode of constitution of real rights, the existence of widespread customary occupation cannot be disregarded where it has continued peacefully, publicly, and without interruption for a period sufficient to evidence an established tenure. Referring to the principles of acquisitive prescription recognised by the civil code and to the transitional provisions of the 2023 Land Code, the Court held that a customary occupant who has farmed the land openly and continuously for more than ten years acquires a real property right that the law recognises and protects, and that this right is opposable to a subsequent holder of registered title. The respondents' family, having farmed the parcel continuously since the 1970s, satisfied that condition.
(2) The 2023 Land Code's general registration requirement does not extinguish pre-existing customary rights, and constructive notice applies to the registered title holder. The Court held that the 2023 Land Code's requirement that all real rights over immovable property be registered is a requirement of form, intended to give public notice of rights and to facilitate the operation of the cadastral system; it is not a substantive rule that extinguishes pre-existing rights that the registered title holder knew or ought to have known about. The Court observed that the cadastral update that had classified the parcel as unallocated domain land had been conducted in a manner that did not, in practice, capture the established customary occupation, and that the claimants themselves, in the course of their pre-acquisition enquiry, had been informed by the local population of the respondents' long-standing presence on the land. In those circumstances, the registered title could not be set up against the respondents' customary right.
(3) The burden of inquiry into the existence of unregistered customary rights falls on the purchaser of registered title. The Court held that a purchaser of registered title who wishes to rely on the conclusive effect of the title against unregistered occupants must, before acquisition, make reasonable inquiry into the existence of such occupants and into the customary arrangements that govern the land. The inquiry is to be conducted at the level of the local community, through the village chief and the customary land council, and is to be documented in the acquisition file. A failure to make such inquiry, where the existence of customary occupation is evident on the ground, precludes the registered title holder from setting up the title against the customary occupant. The claimants had failed to discharge that burden; the inquiry they had conducted was perfunctory and did not contact the village authorities before completion of the acquisition.
This judgment is the leading Mauritanian statement on the coexistence of the formal land-register system and the customary land tenure that, in practice, governs a substantial share of agricultural land, and it arrives at a critical moment in the national cadastral programme. By recognising that customary occupation continued for more than ten years gives rise to an opposable real property right, the Court has confirmed that the formal registration requirement does not operate as a substantive rule that extinguishes pre-existing customary rights; by holding that the registered title holder bears the burden of inquiry into customary occupation, it has shifted the practical risk of cadastral omission onto the purchaser, who is best placed to investigate the conditions of the land before acquisition. The decision carries clear practical guidance for investors, developers, and the cadastral authorities: registrations should not be granted over lands that are visibly occupied without inquiry into the basis of that occupation; the customary land councils are to be consulted as part of every acquisition; and the transitional provisions of the 2023 Land Code are to be applied in a manner that protects established occupants rather than undermining their tenure. Practitioners note the resonance of the Court's reasoning with the customary-tenure jurisprudence of Senegal and Mali, where the same tension between formal registration and customary occupation has been addressed by similar reliance on the principles of acquisitive prescription and on the duty of inquiry of the registered title holder. The case is expected to be cited wherever Mauritanian courts are asked to resolve a conflict between a registered title and a customary holding, and it is likely to influence the development of implementing regulations for the 2023 Land Code.
"The land-register system is an instrument of public notice. It does not create rights; it records them. A customary occupant who has held the land peaceably and publicly for more than ten years has a real right that the law protects, and the holder of a registered title that conflicts with that right cannot set it up against the occupant without having first inquired, at the level of the local community, into the existence of the customary occupation. The burden of that inquiry falls on the purchaser, who is best placed to investigate the conditions of the land before acquisition." — Justice of the Supreme Court of Mauritania