|Madeira Islands - nowdays|
In the 15th century, the Atlantic islands of Spain and Portugal were crucial in the formation of a kind of technological and commercial prototype or template for slave-based sugar production that was transferred to the Americas after 1492.
The Portuguese began colonizing the Madeira Islands (especially Madeira, La Palma, Hierro, and Porto Santo, c. 768 square kilometers) in the early 1420s; the nine islands of the Azores (c. 2,300 square kilometers) in the 1430s or 1440s; and the 10 principal islands of the Cape Verde Islands (c. 4,000 square kilometers), most importantly São Tomé and Principe, in the late 1400s. None of these islands were inhabited. This was not true of the seven Canary Islands (c. 7,300 square kilometers), which were inhabited by a group collectively known as the Guanches.
In the late 1300s, Castilians, Italians, French, and others launched slave-raiding expeditions on the Canaries. The Spanish formally incorporated the Canaries into their empire in 1496 after the subjugation of the islands’ natives, though nominal Castilian rule dated back to the early 1400s.
Together these Atlantic islands provided the aggressively expansive empires of Spain and Portugal with “stepping stones” to the Americas for their nascent sugar and other tropical export industries.
Crucibles of empirical, hands-on experiments regarding all aspects of sugar production—from cultivation and harvest, to the importation and control of African slave labor, to the quasi-industrial processes by which cane juice was transformed into granular sugar—the Atlantic islands were crucial in the development of the technological know-how necessary for the explosion of sugar production in the Caribbean and Brazil in the 16th century and after.
By the late 1450s, sugar production on Madeira exceeded 70,000 kilograms, most exported to England and the Mediterranean, deepening markets and solidifying the financial and commercial networks that would later play a crucial role in the development of plantation-based export production in the Americas.
The administrative infrastructure that the Portuguese developed to rule Madeira, the Azores, and the Cape Verde Islands, based on hereditary “donatary captaincies,” were likewise transferred wholesale to Brazil during the first half-century of its colonization.
Plantation-based sugar production on Madeira in particular, based on both slave and free-wage labor, also whetted the European appetite for this luxury commodity, deepening demand just on the eve of the encounter with the Americas.
In addition both before and after sugar production had become established in the Americas, the Atlantic islands served as important way stations for the African slave trade and for long-distance trade with Asia.