The desire to circumvent Ottoman control of trade routes bringing luxury goods from Asia to Europe was one of the main factors that led to the establishment of the Atlantic slave trade.
In the late fifteenth century, after the Ottomans captured Constantinople, they used their increased political power to dominate Mediterranean trade routes. Inevitably, this meant that Western European powers such as the Portuguese had to find alternative trade routes of their own.
The Portuguese found such routes after landing in West Africa. Here, they discovered a variety of different trade routes dealing in all manner of goods, especially luxury goods such as gold, pepper, and ivory.
They also discovered an extensive trade in slaves. Anxious to get in on this lucrative trade, the Portuguese bought up vast numbers of slaves and shipped them to Portugal and Spain. Before long, slaves were being transported across the Atlantic to the New World, where colonial enterprises such as mining and farming required vast amounts of labor.
Initially, European settlers had relied on Indigenous people for such work, but war, disease, and famine severely depleted the Indigenous population, and so Europeans increasingly turned to African slaves to fill the gap.