3 This trade has been most extensively studied from the eighteenth century onwards. See Orhonlu, Habeş Eyaleti, 98–102, 129–32; Walz, Terence, Trade between Egypt and Bilād as-Sūdān 1700–1820 (Cairo: Institut Français d'Archéologie Orientale, 1978)Google Scholar; Terence Walz, “Gold and silver exchanges between Egypt and Sudan, 16th–18th centuries”, in Richards, J.F. (ed.), Precious Metals in the Later Medieval and Early Modern Worlds (Durham, N.C.: Carolina Academic Press, 1983), 305–25Google Scholar; Kapteijns, Lidwein and Spaulding, Jay, “Precolonial trade between states in the eastern Sudan ca. 1700–ca. 1900”, African Economic History 11, 1982, 29–62CrossRefGoogle Scholar; Spaulding, Jay, “Suakin: a port city of the early modern Sudan”, in Hall, Kenneth R. (ed.), Secondary Cities and Urban Networking in the Indian Ocean Realm, c. 1400–1800 (Plymouth: Lexington Books, 2008), 39–53Google Scholar; Peacock, A.C.S., “Suakin: a northeast African port in the Ottoman Empire”, Northeast African Studies 12 (2012)CrossRefGoogle Scholar.