The unique position held by Ortelius' "Theatrum Orbis Terrarum" in the history of cartography is to be attributed primarily to its qualification as "the world's first regularly produced atlas." Its great commercial success "enabled it to make so great a contribution to geographical culture throughout Europe in the later 16th Century.' Terra Incognita carries reproductions of a number of these fine maps.

Shape and contents set the standards for later atlases, when the center of map-trade moved from Antwerp to Amsterdam.

The characteristic feature of the "Theatrum" is that it consists of two elements, forming a unitary whole - text and maps. This concept for a "Theatre of the world" was followed throughout the 17th Century. Before Ortelius, no one had done this, and thus the chorus of praise which arose as a result was far from slight.

Another important aspect of the "Theatrum" is that it was the first undertaking of its kind to reduce the best available maps to a uniform format. To that end, maps of various formats and styles had to be generalized just like the present-day atlas publisher would do.

Abraham Ortelius himself drew all the maps in manuscript before passing them to the engravers. The first edition consisted of 70 maps on 53 sheets, assembled from the best available sources. At the time of publication, it was the most expensive book ever produced.

The technique used for printing the maps was "intaglio" - copperplates were used, on which the information was engraved by mirror image. Plates were inked, then wiped clean and the ink remaining in the copper grooves was transferred to the damp paper by applying high pressure from a roller. The resulting prints or pulls were hung up to dry.

Texts were composed by setting individual letters in reverse order into rows forming the printed lines, and putting these one beneath another until the text of an entire page had been set. These rows of letters were then fixed on a page block, inked and block pressed on to the paper at relatively low pressure.

Abraham Ortelius was born in Antwerp. After studying Greek, Latin and mathematics, he set up business with his sister, as a book dealer and "painter of maps." Traveling widely, his business prospered and he established contacts with scholars in many lands.

A turning point in his career came in 1564 with the publication of a World Map in Eight Sheets; other individual maps followed and then - at the suggestion of a friend - he gathered together a collection of maps from contacts among European cartographers, had them engraved in uniform size, and issued in 1570 the Theatrum Orbis Terrarum (Atlas of the Whole World).

The Theatrum was the first uniformly sized, systematic collection of maps and hence can be called the first atlas.

Most of the maps were engraved by Frans Hogenberg.

The atlas was an instant success and appeared in numerous editions in different languages, incorporating the latest contemporary knowledge and discoveries. The final edition appeared in 1612.

Between 1570 and 1612 the Theatrum was re-issued in 42 editions with 5 supplements, and with text in Latin, Dutch, German, French, Spanish, Italian and English.

Apart from modern maps in his major atlas, Ortelius himself compiled a series of historical maps known as the Parergon Theatri which appeared from 1579 to 1606, sometimes as a separate publication and sometimes incorporated in the Theatrum.

The number of maps included in the Parergon increased from 4 in 1579 to 43 in 1606, with text in Latin, French, Italian, German and English (1606).

Unlike many of his contemporaries, Ortelius noted his sources of information and in the first edition acknowledgement was made to 87 different cartographers.

Inaugurated by Ortelius and Mercator in 16th Century, the Golden Age found its fullest expression during the 17th Century with the production of monumental multi-volume world atlases in Amsterdam by Joan Blaeu, Jan Jansson, C. Visscher, Abraham Goos, and Frederik de Wit. During that time Antwerp and then Amsterdam became two of the wealthiest trading cities in Europe, and centres of art and printing.

Sixteen Century Dutch Cartographers:

• Gerard Mercator (1512-1594). He was an astronomer, mathematician, cartographer, instrument and globe maker. Mercator surveyed, engraved and produced maps. His sons and grandsons were all cartographers involved in the production of maps and atlases. He is best remembered for Mercator's projection.
• Abraham Ortelius (1527-1598). In 1570 issued the first atlas, "Theatrum Orbis Terrarum." During the next 42 years the Theatrum was re-issued in 42 editions!
• Jodocus Hondius (1563-1612).
• Georg Braun (1541-1622) and Franz Hogenebrg (1535-1590). In 1572 they began to issue the "Civitates Orbis Terrarum," their wonderful six-volume atlas of the world's cities.

Seventeenth Century Dutch Cartographers:

• Willem Janszoon Blaeu (1571-1638) was trained by Tycho Brahe in astronomy. He was a surveyor, globe-maker, and publisher; his sons, also cartographers of considerable esteem, were Joan (1596-1673) and Cornelius (?-1642). Blaeu's Atlases were printed from 1630 to 1662. In 1672 most of the maps and printing presses were destroyed in a fire.
• Jan Jansson (1596-1664). A contemporary and rival of Blaeu. Produced Ptolemy's Geography in 1617 and constructed globes. He issued atlases together with his brother-in law Hondius from 1638.

The Golden Age of Dutch Cartography was made possible by great discoveries of the time. The following are some of the defining moments:

• 1487 Bartholomeu Dias barely touches the Cape of Good Hope.
• 1492 Columbus sets sail and discovers islands in the Caribbean.
• 1494 The Treaty of Tordesillas divides the world between Spain and Portugal for the alleged purpose of spreading Christianity.
• 1497-98 Vasco da Gama rounds the Cape of Good Hope and reaches India.
• 1497 John Cabot spots a "new found land" while searching for Northwest Passage.
• 1504 Venice proposes a Suez Canal to the Sultan of Turkey.
• 1506 Christopher Columbus dies.
• 1519 Magellan begins his journey to circumnavigate the world with five ships and 270 men.
• 1519-38 Hernan Cortes conquers Mexico.
• 1521 Magellan killed by natives in the Philippines.
• 1522 Eighteen of Magellan's crew and one ship return.
• 1534 Jacques Cartier enters the St. Lawrence River. Land in Great Lakes claimed for France.
• 1577 Sir Francis Drake sets sail from England. He circumnavigates the globe.
• 1596 Willem Barents sails to Novaya Zemlya.
• 1600 The English East India Company is founded.
• 1606 Willem Janszoon discovers Australia.
• 1609 Henry Hudson explores present-day New York and Hudson River and claims them for the Dutch.
• 1642 Abel Tasman discovers Tasmania and New Zealand.