Slavery had existed in Europe since ancient times and persisted in various forms throughout the Middle Ages. While classical slavery declined in Northern Europe by the 12th century, it remained common in Southern and Eastern Europe. Various forms of slavery, including the buying and selling of slaves as commodities, began to rise again in Europe in the 15th century, driven by the growth of the sugar industry in the Mediterranean and Atlantic regions. The Portuguese began trading slaves from Africa to Europe in the 1440s and to the Americas after 1450, establishing the transatlantic slave trade that would grow dramatically over the following centuries.