The papers in this section deal with commercial, diplomatic and military diasporas that have settled across the Mediterranean and the Indian Ocean basins since the seventh century. However, the majority of the chapters focus on the modern diaspora, characterized by the development of commercial systems that promoted forced movements of Africans to Europe, the Americas, East Asia, the Indian Ocean islands and the Middle East. The chapters offer a complex view of Global Africa in various parts of the world between the seventh and twentieth centuries, an aspect of which was migration to societies in the Americas, Europe, Africa, the Mediterranean and Middle East, South Asia, China and Oceania. It should be emphasized that these diasporas resulted from several currents that existed for a long time. Most, but not all, were engulfed by the slave trade. An estimated 12,500,00 million people were taken from Africa to the Americas between the beginning of the sixteenth and the end of the nineteenth century (Trans-Atlantic Slave Trade Database). According to Joseph E. Inikori (1982, p. 20), the actual figure was probably much higher, reaching $15,400,000$. Some $14,387,000$ people were taken to the Indian Ocean and Asian regions, between 650-1875 (Austen, 1979, p. 68). In the Mediterranean basin, around 1.7 million Africans were part of the Sahara-Maghrib slave trades between 1550 and 1900 (Austen, 1992, p. 227). The slave trade during the period from the Arab expansion in North Africa (667) to the second half of the sixteenth century 'remains too thinly documented for any direct calculation of its scale' (Austen, 1992, p. 222). Here, the chapter written by Salah Trabelsi is a significant contribution to the documentation of the African presence in the Iberian Peninsula. An important word about the slave-trade numbers: all calculations are based on  
the documents available, which are very limited for some regions and periods. These numbers are therefore estimates and not exact calculations.