Theatrum Orbis Terrarum (pronounced , "Theatre of the World") is considered to be the first true modern atlas. Written by Abraham Ortelius, strongly encouraged by Gillis Hooftman and originally printed on May 20, 1570, in Antwerp, it consisted of a collection of uniform map sheets and sustaining text bound to form a book for which copper printing plates were specifically engraved. The Ortelius atlas is sometimes referred to as the summary of sixteenth-century cartography.