Wine was almost certainly introduced to Portuguese by the ancient Phoenicians, who traded here long before the Romans arrived. There is speculation that they introduced many of the Portuguese grape varieties which certainly seem to have come from a different genetic pool from neighboring Spain. The Muscat of Alexandria planted near Lisbon is also found near Tunisia, home of ancient Carthage. In Sicily it is called 'Zibbibo' named after Cape Zib in Tunisia.
Modern exports developed with trade to England after a treaty in 1703. The Port trade developed rapidly after this. Portugal has the oldest appellation system in the world, the Douro Valley being the first major region to be demarcated. This region produces some of the world's finest, most intense and most unique wines both Port and the Douro reds.
The Dão and Bairrada regions produces flavourful red table wines, which vary between extreme fruitiness and tannic hardness depending on the producer. The newer Alentejo region in the south is perhaps more reliable. The wines here are big and rich, and now modern technology and methods have been introduced, no longer hot and flabby.
Much of the wine from the north is described as 'Verde' or green. It can be red. The green means young or fresh. Red Verde is rarely to international tastes. White Verde can be, especially if it is made from Alvarinho or Loureiro grapes. Light fresh, semi aromatic wine with a green tang - great in a hot climate or with fish!
Interestingly, Portugal has two wine producing regions protected by UNESCO as World Heritage: the Douro Valley Wine Region (Douro Vinhateiro) and Pico Island Wine Region (Ilha do Pico Vinhateira).
Portugal has a large variety of native breeds (about 500), producing a very wide variety of different wines with distinctive personality. The Oxford Companion to Wine describes the country as having "a treasure trove of indigenous grape varieties." With the quality and uniqueness of its wines, the country is a sizable and growing player in wine production, being in the top 10, with 4% of the world market (2003).
The country is considered a traditional wine grower with 8% of its continental land dedicated to vineyards. Unlike most latin wine producing countries wine consumption in portugal appears to be stable. Until recently it was actually increasing.