For over two centuries, the name DOW has been associated with the finest port from the vineyards of the Upper Douro. During the 20th and 21st centuries, the Symington family built upon the legacy of the earlier Silva and Dow families. Generations of Symington winemakers have worked the Dow vineyards: Quinta do Bomfim and Quinta da Senhora da Ribeira, creating from them the superbly concentrated Dow wines that are intense and tannic when young, maturing to a sophisticated and alluring elegance with age and perfumed with aromas of violet and mint. The attractive and distinctive dry finish of Dow is the recognizable hallmark of the wines from this great Port house.

The story of Dow's is unusual among all the great Port houses. It all began in 1798, when Bruno da Silva, a Portuguese merchant from Porto, took a journey opposite to that of the first British merchants. Bruno settled in London, from where he imported wine from his native country. He married an Englishwoman and was quickly assimilated into London society, where his business acumen led to an excellent reputation for his wines. But the outbreak of the Napoleonic Wars put his business at risk. Undeterred, Bruno da Silva applied for 'letters of marque' (Royal Assent to equip a merchant ship with weapons) to ensure safe passage from his Port of Porto to Bristol and London. He became the first and only port company to transport his precious cargo of barrels from good ports under his own armed protection through the treacherous Bay of Biscay.

The port transport business was continued by Bruno's son, John da Silva, who in 1862 brought in the partnership of Frederick William Cosens. Together with John's son, Edward, they became the active partners of Silva & Cosens. Edward da Silva inherited his grandfather's business acumen, and the company continued to prosper. Edward became a highly respected figure in the London wine trade and was one of the founders of the Wine Benevolent Society, the leading charity that survives to this day as the principal British wine trade organisation. Edward da Silva would be the president of the Benevolent and then, from 1892, its chairman for many years.
With the continued expansion of the company, Edward da Silva and Frederick Cosens joined forces with George Acheson Warre, whose well-known family had been involved in the port trade since its early years. GAW joined as a partner in 1868 and became its driving force in Portugal.

In 1877, Silva & Cosens merged with another leading port company, Dow & Co., whose main partner was James Ramsay Dow, who had distinguished himself in 1856 with the publication of his important treatise, 'Inquiry into the Fungus Suggestions for a Remedy'. At the time, the Oidium fungus was devastating the vineyards of the Douro.
Although smaller than Silva & Cosens, Dow & Co had become a highly regarded port producer, with a particularly good reputation for its Vintage Ports, and when the two companies merged, it was decided to adopt DOW'S as the brand.