CORSCICA / SARDINIA / Per Gerardum Mercatorem.

This is an attractively engraved map by Gerard Mercator of the islands of Corsica and Sardinia. The two maps are on one folio sheet. Like all of Gerard Mercator's maps of Italy, numerous cities, towns, and villages are identified on the map. At the bottom of the Corsica map is a portion of the island of Sardinia, and at the top of the Sardinia map is a part of the island of Corsica.
Gerard Mercator (1512-1594) was one of the most famous geographers of his time. He was renowned as a scholar in his day, and his name is known to this day as the inventor of the map projections named after him. His maps are known for their precise geographic information and for their attention to detail. All of his maps are finely engraving, mostly by Mercator or by one of his family members. He worked initially from Leuven, Flanders, but then from Duisberg in Germany. Around 1563, Mercator became cosmographer to Duke William V of Julich, Kleve.. in Germany.
As the cosmographer, he began the writing of a Cosmography intended to cover, in five volumes, the entire known world. As Mercator was involved in all aspects of the time-consuming Cosmography, from writing the text, drawing the maps, and engraving the copperplates, the atlas was not finished in his lifetime and only sections were finished and published before his death. His son, Rumold, along with other family members finished the various parts and published the final product, including previously published parts, as the Atlas Sive Cosmographicae... in 1595.
In 1589, Gerard Mercator published his section on Italy, including this map, and the surrounding parts of Europe as the Italiae Sclavoniae et Graeciae Tabulae Geographicae. The map also was used for Mercator's Atlas Sive Cosmographicae... in 1595. One further edition of this atlas was published by the Mercator family in Duisberg in 1602 with this same map. In 1604, the copperplates for the atlas were sold to Jodocus Hondius and Cornelis Claesz. In 1606, Hondius introduced a completely revised edition of Mercator's atlas, Atlas sive Cosmographicae...... and used this map from the Mercator plates for inclusion in the atlas, or as it is often called, the Mercator-Hondius atlas.

Jodocus Hondius (1563-1612) was the founder of the famous 17th century Dutch map publishing family. Hondius, along with sons Jodocus II and Henricus and son-in-law Johannes Janssonius, was prominent in Dutch cartography and his family competed aggressively with the emerging Blaeu family map business. 
This particular map appeared in the Latin edition of the Mercator Hondius Atlas of 1613 with a signature of "Ssssss" and page "302-303" on the verso.  The verso of the map has information in Latin on Corsica and Sardinia. This map last appeared in 1635 in Janssonius' Theatrum Italiae, after which it was replaced with other maps of the region by the Hondius and Janssonius publishing firm (van der Krogt, p. 695).

Reference: Van der Krogt, Peter. Koeman's Atlantes Neerlandici, vol. 1. 't Goy-Houten: HES Publishers,1997.