A fine example of one of the most memorable of Ortelius' maps, first issued in his 'Theatrum' in 1590.

It features an array of mythical sea monsters, copied from the famous woodblock in Munster's 'Cosmographia' of 1540. In turn, these were copied from the earlier works of Olaus Magnus, a Swedish ecclesiastic who spent much of his life in Rome.

The monsters are keyed to an explanation on the verso text. The English translation is:

A. is a fish, commonly called NAHVAL. If anyone eats of this fish, he will die immediately. It has a tooth in the front part of its head standing out seven cubites in length.
B. the Roider is a fish of one hundred and thirty ells in length, which has no teeth. The meat of it is very good, wholesome and tasty. Its fat is good against many diseases.
C. The BURCHVALUR has a head bigger than its entire body. It has many very strong teeth, of which they make chess pieces. It is 60 cubites long.
D. The Hyena or sea hog is a monstrous kind of fish about which you may read in the 21st book of Olaus Magnus.
E. Ziphius a horrible sea monster that swallows a black seal in one bite
F. The English whale, thirty ells long. It has no teeth, but its tongue is seven ells in length.
G. HROSHUALUR, that is to say as much as sea horse, with manes hanging down from its neck like a horse. It often causes great scare to fishermen.
H. The largest kind of whale, which seldom shows itself. It is more like a small island than like a fish. It cannot follow or chase smaller fish because of its huge size and the weight of its body, yet it preys on many, which it catches by natural cunning which it applies to get its food.
I. SKAUTUHVALUR. This fish is fully covered with bristles or bones. It is somewhat like a shark, but infinitely bigger. When it appears, it is like an island, and with its fins it overturns ships.
J.
K. SEENAUT, sea cow of grey colour. They sometimes come out of the sea and feed on the land in groups. They have a small bag hanging by their nose with the help of which they only live in the water. If it is broken, they live altogether on land, accompanied by other cows.
L. STEIPEREIDUR, a most gentle kind of whale, which for the defence of fishermen fights against other kinds of whales. It is forbidden by proclamation that any man should kill or hurt this kind of whale. It has a length of at least 100 cubits.
M. STAUKUL. The Dutch call it Springval. It has been observed to stand for a whole day long upright on its tail. It derives its name from its leaping. It is a very dangerous enemy of seamen and fishermen, and greedily goes after human flesh.
N. ROSTUNGER is somewhat like a sea calf. It goes to the bottom of the sea on all four of its feet, which are very short. Its skin can hardly be penetrated by any weapon. It sleeps for twelve hours on end, hanging on some rock by its two long teeth. Each of its teeth are at least one ell long and the length of its whole body is fourteen ells.
O. Spermaceti or a simple kind of amber, commonly called HUALAMBUR
P. Blocks and trunks of trees, by force of winds and violent tempests torn off by their roots from the cliffs of Norway, tossed to and fro, and surviving many storms finally cast upon and coming to rest at this shore.
Q. Huge and marvellously big heaps of ice, brought here by the tide from the frozen sea, making loud and terrible noises. Some pieces are often as high as forty cubits. On some of these, white bears sit together, to catch fish.

Abraham Ortelius (1527-1598) took an active interest in cartography from an early age. He began his career as a "kaarten afzetter" (illuminator of maps) purchasing single (generally wall) maps from booksellers and colouring them for re-sale. He travelled extensively in his search for new material and was a well-known face at the Frankfurt bookfairs. It was whilst travelling that Ortelius built up his unrivalled web of contacts, which included many of the leading historians, scientists, and cartographer's of the day.

These contacts would prove invaluable in the compiling and completion of his 'Theatrum orbis Terrarum' first published in 1570. The work was "the first true atlas" (van der Broecke): all the maps were of a uniform size and style, with an engraved title, accompanying text, and - hitherto unheard of in cartographic publications - a list of the source material. With its comprehensive scope, the atlas was a huge step forward compared with the contemporary "Lafreri" atlases, which were bound up to order and so reflected the whims of the customer. Even though it was the most expensive work published at the time, it proved an instant success with four versions of the first edition being printed in 1570 alone. The work would go on to be published for 42 years, with some 31 editions being produced.