The first Europeans arrived in Japan by accident. There was a fuzzy idea of its existence from Marco Polo’s account of “Zipangu,” as a country covered with silver and gold, and traders in Southeast Asia must have known of its existence but no expeditions were specifically sent in order to find it. Instead, three armed Portuguese, on a Chinese junk, drifted to Tanegashima, an island off the southern coast of Kyūshū, in 1543. So began a century of productive cross-pollination between Japan and the Western world.
In Japan this was known as the period of Warring States. The shogun still held office in Kyoto but political decay had resulted in a century of armed conflict throughout the land. As a result, the harquebuses (an early gun so large and heavy it required a support) carried by the Portuguese that arrived in Tanegashima were copied and mass-produced in less than a decade. As guns came to be included in the arsenal of the Japanese warrior, this dramatically affected warfare. Instead of the battles strategized to make use of cavalry, infantry became much more important. The first battle where guns are considered to have made a decisive difference in the outcome was the Battle of Nagashino in 1575, in which Oda Nobunaga defeated Takeda Katsuyori.
Equally important was the arrival of the Jesuit missionary St. Francis Xavier. Founder of the Society of Jesus with Ignatius Loyola, he was ordered to the Far East by the pope in 1540. After working in India, Malacca, the Moloccas, and Motorai (an island near the Philippines), he arrived in Japan in 1549. He spent two years in Japan, traveling from Kyūshū to Kyoto, and he moved on to China, which he believed was the key to converting the entire East. Xavier and his party were followed by others who set about establishing a Christian community based in Kyūshū. In 1580, in hopes of attracting foreign trade, the local daimyo granted the Jesuits the port of Nagasaki. The Jesuits converted through education, introducing many Western concepts that had nothing to do with religion. These acts included the establishment of a printing press with moveable type to print religious tracts, instruction in oil painting which was a new medium for the Japanese, and Western medical techniques.