Global Spread of Maize in the 17th Century

Timeline

1. c. -7000–-5000Tehuacán Valley, Mexico · Puebla StateInfluenza indigenous peoples of the central Mexican highlands gradually bred cultivated maize with larger cobs and more kernels through long-term artificial selection of wild teosinte (Balsas teosinte, Zea mays ssp. parviglumis). This domestication process took thousands of years, ultimately producing the ancestor of modern high-yielding maize. Maize then became the staple foundation and core religious symbol of Mesoamerican civilizations (Olmec, Maya, Aztec), and had already spread from Mesoamerica to the American Southwest and the Andes of South America in the pre-Columbian period.
2. 1493–1600Iberian Peninsula and Mediterranean coast · Iberian PeninsulaColumbus brought maize samples back to Spain on his first return voyage in 1493, after which European botanists recorded it as the curious 'wheat of the Indies' (trigo de Indias). In the early 16th century, maize began to be cultivated on a small scale in southern Spain, Portugal, and northern Italy (Veneto, Friuli), mainly as a garden curiosity or livestock feed. The Ottoman Empire obtained maize seeds through Venetian and North African trade channels and began promoting its cultivation in the Balkans (Moldavia, Wallachia) by the mid-16th century, where it was known as 'Turkish wheat' (mısır).
3. 1651–1660West Africa, South Asia, and East Asia · GlobalIn the mid-17th century, the spread of maize entered a global peak phase. In West Africa, Portuguese and Dutch traders dispersed maize along the Gulf of Guinea coastline, where local farmers quickly adopted it for its high yield and drought tolerance, using it as a food reserve to provision slave ships; in Asia, maize reached the western Indian subcontinent via Portuguese Goa and Southeast Asia as well as China's Fujian and Guangdong provinces via Malacca; Chinese records by the mid-17th century already extensively documented the cultivation of 'yushumu' (maize). Northern Italy (the Po Plain), the Balkans, and northern Iberia also incorporated maize into their agricultural rotation systems during this period to make up for food shortfalls caused by population growth.
4. c. 1700–1800Balkans, northern Italy, and sub-Saharan Africa · Southeastern EuropeIn the 18th century, maize completed its transition from supplementary crop to staple in the Balkans (especially Romania and Serbia), northern Italy (where polenta became a staple food), and parts of West Africa. This transformation formed a positive feedback loop with population growth: maize's high caloric density allowed the same land area to support more people, driving population expansion in parts of Europe and Africa in the 18th century. However, heavy reliance on a maize-only diet also brought the public health problem of pellagra (niacin deficiency), revealing the potential risks of rapid dietary change.