The African Union has not legally defined specific working languages, though they do say that the working languages "shall be, if possible, African languages, Arabic, English, French and Portuguese." The prominence of Arabic in many African countries is due to the Arab expansion into Africa from the 7th century, with subsequent Arabization of local populations. Indo-European languages were introduced during the European colonisation from the 15th century.
In 2001, the AU created the African Academy of Languages (ACALAN) to harmonize the various languages across the continent and safeguard any that are on the verge of becoming extinct. To that end, the AU declared 2006 the Year of African Languages. 2006 also marked Ghana's 55th anniversary since it founded the Bureau of Ghana Languages originally known as Gold Coast Vernacular Literature Bureau.