This compact area of just under 200 thousand square kilometers contains the lower courses of the chief headwaters of the Sénégal River, and the upper course of the united river. The Bafing, regarded as the true source of the Sénégal, flows into Kayes from the south and joins the Bakoy just west of the region's center. The Bakoy enters Kayes from the southeast, and receives the Baoule on its right before joining the Bafing. The Baoule also enters from the southeast, and then forms part of the eastern border before turning west--the Boucle de(1) Baoule.
The remaining important river, the Falémé, enters from the southwest and marks the western boundary of Kayes, joining the Sénégal at the three-way international border at the region's northwest.
The chief lake, Manantali, is formed by the damming of the Bafing.
Less than two million people live there. The majority speak Mandekan as their first language(2). In the north of the region Soninke is spoken; these speakers account for nearly one in three in Kayes. The only other first language accounting for as many as one in 20 is Pulaar (or Pular), the local name for the language of the Fulani(3). Some learn French, the government's language, and many learn classical Arabic, the religious language.
Most people are Moslems, albeit with a degree of syncretism that reflects older, local beliefs.
Kayes, the administrative center the region is named for, is the largest city by a small margin, but still has less than 100 thousand residents. Kayes marks one of the limits on river navigation.(4)
Mande languages, like Mandekan and Soninke, have been spoken in the area for more than 2,000 years--about the time differentiation within the group developed. The Fulani first entered the area, from downstream, in the last few centuries.
Arabs introduced Islam in the tenth century. Throughout the Soninke empire, which extended beyond Kayes in all directions, Islam replaced the rulers' local religion, characterized by belief in spirits and a deus otiosus.
The French conquered Mali during the 19th century and yielded control in the 1960s, leaving their language to the new government.
(1) Translates from French as 'bend of', in this context.
(2) The Maninkakan and Xaasongxango (or Khassonka) dialects are often considered as separate languages. Their mutual intelligibility is aided by the oral transmission of epics in the older, standard, dialect. Xaasongxango is, however, less standard than Manikakan. The collection is sometimes also called Manding or Mandingo.
(3) Often called Fulfulde elsewhere.
(4) The other is far upstream. The difference can be accounted for by either seasonal changes in water levels, or the size of boat under consideration.