How Port Became a Wine Staple Through Trade Agreements

Port is one of the most iconic and popular fortified wines in the world. Its rich, sweet flavor makes it an ideal wine for celebrations and special occasions. But how exactly did port become such a globally renowned wine? A large part of port’s rise to prominence is due to strategic trade agreements between Portugal and England centuries ago.

The Origins of Port in Portugal

Port is made in the Douro region of Northern Portugal. This region has been growing grapes and producing wine since at least the time of the Roman Empire, and possibly even before. Wine from the Douro was exported throughout history, especially in the 12th century. But the Douro became world-famous thanks to help from an unlikely source, English merchants.

English – Portuguese Trade Agreements

Treaty of Windsor

In 1386 the Treaty of Windsor was passed between England and Portugal. This treaty allowed merchants to live and work in the the other’s country without any added tariffs or taxes. Trade between the countries started to flourish, and Portuguese wine quickly became one of the main English imports.

The Anglo-Portuguese Commercial Treaty of 1654

This next treaty gave English merchants in Portugal special treatment and a lower customs fee. The amount of wine the English imported continued to increase. Then a little over a decade after this treaty was passed, a trade war between France and England erupted. This trade war eventually ended with a ban on French imports into England, although the ban didn’t last long, it boosted the amount of wine coming from Portugal.

At this time much of the wine was coming from the Minho region in Portugal, north of both Porto and the Douro region. But the wine from here was a light, often overly acidic red wine that was unpopular with many English wine drinkers. So the English merchants, who suddenly found themselves with a very favorable market, went in search of a higher quality wine. They found exactly what they were looking for in the Douro Valley. The only issue was getting the wine from the interior region of Douro to the English ships on the coast. The easiest way to transport the wine was to ship them by the Douro River, which eventually meets the Atlantic Ocean in Porto. And once the wine arrived in Porto it could be easily loaded on ships bound for England. So English merchants set up their businesses in Porto, which is why wine from the Douro started being called Porto or Port in English.

The Methuen Treaty of 1703

The Methuen Treaty further solidified Port as an English staple by once again giving preferential trading status between Britain and Portugal. This treaty came about when Portugal needed British military assistance in the War of Spanish Succession. As part of the treaty, Portugal granted preferential tariff rates for British textiles while Britain agreed to import Portuguese wines at a lower duty than those from other nations. Specifically, the treaty stipulated that Portuguese wines imported to England would pay only two-thirds the duty of French wines. This made Portuguese wines, including Port, significantly more affordable and competitive in the British market.

The Evolution of Port

Today, Port is made by adding brandy in the middle of the fermentation process. The brandy kills the yeast and stops the fermentation which allows the wine to remain sweet. But this process of making Port is relatively modern. Before the mid 18th century Port was made very differently. It was not sweet, and very little of it was fortified; it was just a dry red wine. Though by the 18th century a small amount of merchants that would fortify their wine with brandy to keep the wine from spoiling on the long journey to England. But the brandy was added after the wine had completely finished fermenting, so the wine would remain dry.

It wasn’t until the later part of the 18th century that a few merchants realized if they added brandy during the fermentation they could produce a sweet, rich wine that was very popular with the British. But making Port this way didn’t become widespread until the 1840’s. Legend says that the 1820 vintage in Douro produced such a ripe, full bodied red wine that the only way to recreate it in the following vintages was to fortify the wine.

Did you know? The first demarcated wine region was created in the Douro in the 1750’s. Its creation was due to attempts to produce fraudulent Port in regions outside the Douro and with ingredients designed to cover up poorly made wine. With the creation of the demarcated region, Port producers sought to regulate the production and marketing of wines made in the Douro region, thereby ensuring the quality of all wines labeled Port.

Port wine region Duoro

The Lasting Influence of England in Port

Many of the top Port houses today like Taylor’s, Graham’s, and Cockburn’s were all founded by English families who had established themselves as Port producers in Portugal. These firms came to dominate the Port industry. Many of the early Port houses invested heavily in their facilities and cellars in Vila Nova de Gaia, just outside Porto, where port was traditionally stored and aged while awaiting shipment. The centuries-old Port lodges established here remain centers of Port production and tourism today.

Besides focusing on Port production, the English families also became influential in civic development in Porto and introduced many elements of British culture. Their presence helped shape the city itself. Many streets and buildings still boast British names, illustrating the enduring influence even in Porto’s urban fabric.

The treaties and trade relationships between Portugal and England over centuries were vital in transforming Port from a regional wine to one of the most famous fortified wines in the world.

On this day

January 27: International Port Wine Day


Fladgate, Taylor. n.d. “History of Port – Taylor Fladgate.” Accessed September 24, 2023.

Want to read more about Port? Try out these books!

Port and the Douro (Classic Wine Library) Rich, Rare & Red- A Guide to Port