Between the Niger River and Lake Chad lay various Hausa Kingdoms, encompassing the cultural-linguistic area known as Hausaland which straddles the modern Niger-Nigeria border. The origins of the Hausa are obscure, though they are thought to be a mixture of autochthonous peoples and migrant peoples from the north and/or east, emerging as a distinct people sometime in the 900s–1400s when the kingdoms were founded. They gradually adopted Islam from the 14th century, though often this existed alongside traditional religions, developing into unique syncretic forms; some Hausa groups, such as the Azna, resisted Islam altogether (the area of Dogondoutchi remains an animist stronghold to this day). The Hausa kingdoms were not a compact entity but several federations of kingdoms more or less independent of one other. Their organisation was hierarchical though also somewhat democratic: the Hausa kings were elected by the notables of the country and could be removed by them. The Hausa Kingdoms began as seven states founded, according to the Bayajidda legend, by the six sons of Bawo. Bawo was the only son of the Hausa queen Daurama and Bayajidda or (Abu Yazid according to certain Nigerien historians) who came from Baghdad. The seven original Hausa states (often referred to as the 'Hausa bakwai') were: Daura (state of queen Daurama), Kano, Rano, Zaria, Gobir, Katsina and Biram. An extension of the legend states that Bawo had a further seven sons with a concubine, who went on to the found the so-called 'Banza (''illegitimate'') Bakwai': Zamfara, Kebbi, Nupe, Gwari, Yauri, Ilorin and Kwararafa. A smaller state not fitting into this scheme was Konni, centred on Birni-N'Konni.