While the practices of conquest and empire building have existed throughout human history, the term imperialism came into use only in the late nineteenth century; it refers to a variety of modes and operations by which one society may dominate and control another. Imperialism includes the traditional direct modes of conquest and subjugation practiced by premodern empires such as the Egyptians, Romans, and Mongols and also such modern indirect modes of influence as mercantilism, semicolonialism, and forced cultural assimilation. The early-modern and “high” modern periods, which roughly span the sixteenth through nineteenth centuries, witnessed three great waves of imperialism. The first was the period of Catholic exploration and conquest carried out by the Spanish and Portuguese empires in the sixteenth and seventeenth centuries; the second was the age of mercantilism, best represented by the Dutch and English commercial colonialism of the seventeenth and eighteenth century.