During the Middle Ages, spices became extremely valuable, with sought-after varieties primarily found in Southeast Asia. Naval technologies, including ships and navigational instruments like compasses and sea charts, continued to develop as nations traded ideas. While there were moments of religious tolerance, there were also violent disputes and even wars, such as the expulsion of Muslims and Jews from certain parts of Europe and the Mediterranean. As the cost of spices skyrocketed, Venice and Genoa exploited their position in the Black Sea, eventually gaining control over critical overland trade routes to India, China, and Southeast Asia. In response, European explorers set sail to find cheaper and quicker trade routes, starting with Portugal and Spain.