Atlas «Theatrum Orbis Terrarum» ("Theatre of the World") is considered to be the first true modern atlas. Written by Abraham Ortelius 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. Many of his atlas' maps were based upon sources that no longer exist or are extremely rare. Ortelius appended a unique source list (the "Catalogus Auctorum") identifying the names of contemporary cartographers, some of whom would otherwise have remained obscure. After the initial release of Theatrum Orbis Terrarum, Ortelius regularly revised and expanded the atlas, reissuing it in various formats until his death in 1598. Three Latin editions of this Atlas (besides a Dutch, a French and a German edition) appeared before the end of 1572; twenty-five editions came out before Ortelius' death in 1598; and several others were published subsequently, for the atlas continued to be in demand till about 1612. From its original seventy maps and eighty-seven bibliographic references in the first edition (1570), the atlas grew through its thirty-one editions to encompass 183 references and 167 maps in 1612. Since the 1630s, the Blaeu family issued their work under a similar title "Theatrum orbis terrarum, sive, Atlas Novus".