As a noun in Old English as Africanas "Africans" (only plural). From LatinAfricānae. In Middle English as Aufrican . Early Modern English Aphricane, Africans. The adjective appears in the 16th century, as Affricane, Africane, African.
The Latin Africus is from Afrī (singular Afer), the name of an ancient people of North Africa (near Carthage, in modern Tunisia). Africānus is formed by addition of the -ānus suffix.