The history of mankind is also a history of movement, of mobility, of pushing out horizons. Initially, mainly crusaders, soldiers, messengers, and pilgrims were on the move, but mobility increased in the age of humanism. During the sixteenth century, metropolises of trade and science emerged, and business opportunities for traders expanded. Travel for religious, educational, or scientific reasons made Rome, Naples, Paris, and Strasbourg focal points for many young nobles, scholars, and artists.