Tobacco was unknown in Europe before 1492, and it carried a negative stigma at first. The early Spanish explorers considered native people's use of tobacco to be proof of their savagery. However, European colonists then took up the habit of smoking, and they brought it across the Atlantic. Europeans ascribed medicinal properties to tobacco, claiming that it could cure headaches and skin irritations. Even so, Europeans did not import tobacco in great quantities until the 1590s. At that time, it became the first truly global commodity; English, French, Dutch, Spanish, and Portuguese colonists all grew it for the world market.