“This article covers African literary works from Chad to Tanzania and from Senegal to Ethiopia. The first among the scripts used in Africa below the Sahara was the ancient South-Arabian script with the oldest inscriptions dating back to between the 9th and 7th century BC, written in Sabaic that was used indigenously in the pre-Axumite Kingdoms of Ethiopia notably D‘mt.”

source; https://uncensoredopinion.co.za/the-history-of-writing-in-sub-saharan-africa-including-the-most-notable-literary-works-written-by-african-authors-about-african-history-from-from-the-2nd-century-bc-to-the-19th-century-ad/#