The ethnic groups of Senegal today live in relative peace and harmony, despite their diversity and differences in economic advancement. The main ethnic groups are the Wolof, the Serer, the Fulfulde (Peulh or Fula), the Jola (Diola), the Tukulor, the Lebou, the Niominka, the Bassari and the Bambara. Other cultures include the Moors (Maures or Naar), the Lebanese, and the French. Linguistically, the Wolof have become dominant, and the Wolof is the most widely spoken language in Senegal, as a first or second language; French is the second-most-widely spoken second language. The Serer Language is a group of related but mutually-unintelligible languages: Serer-Sine, Serer-Safen, Serer-Mont-Roland (Serer-Ndut), Serer-Palor and Serer-Nuun.
Various kingdoms and empires have ruled various parts of Senegal. Eastern Senegal was once part of the Empire of Ghana. The Kingdom of Tekrur was founded by the Tukulor in the middle valley of the Senegal River. The senegalese Empire of Jolof (Diolof) at one time included the Kingdoms of Waalo, Biffeche, Bethio, Cayor, Baol, and parts of Sine and Saloum. All of these later split from Jolof, which remained as a kingdom until conquered by the French. The kingdoms of Saloum, Sine and Biffeche continue today along with tributary monarchies like Gandiaye, and the hereditary Princes of Bethio and Jolof (whose kingdoms no longer exist) are still locally revered. The Layene today is a small theocracy of the Lebou people, at Yoff near Dakar, ruled by a Grand-Khalifa. Waalo, Cayor, Beetyo were ethnic Wolof kingdoms, while Sine, Saloum and sometimes Baol were ethnic Serer kingdoms. The Biffeche kingdom has passed among different ethnic groups. The empire of Jolof was of course dominated by the Wolof ethnic group (derived from that word). Waalo, followed by Jolof, Cayor, Baol, Sine and Saloum were all conquered by the French in the 19th Century.
A noteworthy feature of the Wolof, Serer and other ethnic groups is a somewhat rigid "caste" system with complicated classes. The Diola are more egalitarian. There is a paradox in that the modern, democratic Senegal state has abolished most official caste distinctions, yet most Senegalese cling to, and many often enjoy, their inegalitarian traditions.
Separate from the institutions of the state, and from the kingdoms, is the important system of Muslim brotherhoods of Senegal, including the Xaadir (Qadriyya), the Tijanes (Tidianes) and the Mourides. These are a powerful influence in Senegalese life and politics.
The two main recent exceptions to the ethnic harmony described above are an ongoing, low-level violent struggle for autonomy, mostly by Diola, in Casamance in the South (south of The Gambia), and, in 1989-1993, a series of violent black attacks on the Moors in retaliation for violent attacks on blacks in Mauritania, which erupted from a single dispute over a grazing camel. Most Moors left Senegal after hundreds were killed.