” The origin and history of coffee dates back to the 10th century, and possibly earlier with a number of reports and legends surrounding its first use. The native (undomesticated) origin of coffee is thought to have been Ethiopia. The earliest substantiated evidence of either coffee drinking or knowledge of the coffee tree is from the 15th century, in the Sufi monasteries of Yemen. By the 16th century, it had reached the rest of the Middle East, South India (Coorg), Persia, Turkey, Horn of Africa, and northern Africa. Coffee then spread to the Balkans, Italy and to the rest of Europe, to South East Asia and then to America.
Ethiopian ancestors of today’s Oromo ethnic group were the first to have recognized the energizing effect of the native coffee plant. Studies of genetic diversity have been performed on Coffea arabica varieties, which were found to be of low diversity but with retention of some residual heterozygosity from ancestral materials, and closely related diploid species Coffea canephora and C. liberica; however, no direct evidence has ever been found indicating where in Africa coffee grew or who among the natives might have used it as a stimulant or known about it there earlier than the seventeenth century. The original domesticated coffee plant is said to have been from Harar, and the native population is thought to be derived from Ethiopia with distinct nearby populations in Sudan and Kenya.” https://en.wikipedia.org/wiki/History_of_coffee