Hummay founds the Sayfawa dynasty: Islam at the court of Kanem

Kanem, a kingdom of herders and traders north-east of Lake Chad first mentioned by al-Ya'qubi in the 9th century, was ruled by the Duguwa dynasty, which Arab writers connected with the Zaghawa. Its early history is known mainly from the girgam, the royal chronicle, handed down orally and written down only in the 19th century, which gives the names and reign lengths of the kings but no dates; the reconstructions that count backwards from later kings differ, for Hummay's accession by a decade and more. The first ruler associated with Islam was Hu, or Hawwa — a feminine name, which has led some historians to think the ruler was a woman — followed by Selema, also called Abd al-Jalil.

The chronicle calls Hummay Selema's son but treats his accession as the start of a new line: "we shall now proceed to set down the history of the Banu Hummay, who professed Islam". Since Hu and Selema were already Muslims, historians suggest that Hummay overthrew Selema, perhaps with the help of a pro-Islamic faction at court, perhaps as a Sunni displacing Ibadi Muslims, and that the change may be linked to the possible expulsion of the Zaghawa, who in the 12th century appear as nomads outside Kanem. Later tradition credited a scholar named Muhammad ibn Mani with converting the dynasty. Hummay was probably of local, perhaps Kanembu, origin, but his descendants claimed descent from the Yemeni hero Sayf ibn Dhi Yazan, from whom the name Sayfawa derives. He reigned for 12, 22 or 23 years, by different versions of the king list, and died in Egypt, apparently on the pilgrimage to Mecca, and his son Dunama I succeeded him.

Under the Sayfawa, Kanem, which in the 11th century extended its control to the salt-producing Kawar oases on the road to the Mediterranean, became an increasingly Islamic and literate society: by the 12th century its scribes had developed their own style of writing. The dynasty reached its height under Dunama II Dibalemi in the 13th century, moved west of Lake Chad to Bornu in the late 14th and ruled until 1846, one of the longest-lived dynasties in world history.