The Treaty of Windsor (1386): The World's Oldest Alliance Still in Force

On May 9, 1386, Portugal and England signed the Treaty of Windsor, establishing the world's oldest alliance between nation-states still in force. This wasn't just a political arrangement—it was a cultural exchange that would influence both languages and shape centuries of history.

The Beginning: 1373 and Before

The formal alliance actually predates Windsor. The Treaty of London (1373) established an Anglo-Portuguese friendship, but Windsor transformed it into something deeper—a "perpetual" alliance sealed by royal marriage.

Why Portugal and England?

The alliance made strategic sense:

• Common enemies: Both kingdoms opposed Castile (Spain)
• Trade routes: Portuguese wine and English wool created commercial ties
• Geographic positioning: Portugal's Atlantic ports were crucial for English trade
• Religious alignment: Both were Catholic, and later both broke with Rome

The Royal Marriage

The Treaty of Windsor was sealed with the marriage of King John I of Portugal to Philippa of Lancaster, daughter of John of Gaunt (one of the most powerful men in England).

Philippa brought English influence to the Portuguese court:

• English courtiers arrived in Lisbon
• English vocabulary entered Portuguese
• Educational reforms based on English models
• Closer diplomatic ties between the kingdoms

Their children became known as the Ínclita Geração (Illustrious Generation), including: - Prince Henry the Navigator (who launched Portugal's Age of Exploration) - King Duarte I (who wrote a treatise on saudade) - Prince Fernando the Saint

Linguistic Exchange

The treaty facilitated lasting linguistic exchanges:

Portuguese Words in English

The alliance and subsequent trade brought Portuguese words to English:

• Marmalade (from marmelada)
• Cobra (from cobra de capelo)
• Fetish (from feitiço)
• Caste (from casta)
• Albatross (from alcatraz)
• Molasses (from melaço)
• Palaver (from palavra)

English Words in Portuguese

Traffic went both ways, especially in later centuries:

• Futebol (football)
• Bife (beef → steak)
• Pudim (pudding)
• Clube (club)
• Greve (from "strike," via French)

The Alliance Through History

The 15th-16th Centuries England supported Portuguese exploration and received spices, sugar, and news from the new worlds Portugal discovered.

The 17th Century After Portugal regained independence from Spain (1640), England was the first country to recognize the new king. The marriage of Catherine of Braganza to Charles II of England (1662) brought: - The customs of tea drinking to England - The concept of the "fork" to English dining - Bombay and Tangier as dowry gifts - Renewed alliance commitments

The Napoleonic Wars Britain's Duke of Wellington helped liberate Portugal from Napoleon's forces. The Battle of Buçaco (1810) saw British and Portuguese troops fighting side by side.

World War I Portugal entered WWI in 1916 at Britain's request, sending troops to the Western Front.

World War II Portugal remained neutral but allowed Britain to use the Azores as a military base—invoking the Treaty of Windsor explicitly. Winston Churchill quoted the alliance in Parliament as justification for the arrangement.

The Falklands War (1982) Portugal supported Britain's position and allowed use of the Azores for military logistics.

Modern Era Both nations are NATO members and EU partners (until Brexit). The alliance remains symbolically and practically important.

Cultural Connections

Beyond diplomacy, the alliance fostered deep cultural ties:

Port Wine The Methuen Treaty (1703) gave Portuguese wine preferential access to England. English merchants settled in Porto and developed the port wine trade. Many famous port houses—Sandeman, Taylor's, Graham's—have British origins.

The British in Lisbon A substantial British community has existed in Lisbon for centuries. The St. George's Church in Lisbon dates to 1622.

Football British workers introduced football to Portugal in the late 19th century. Portugal's oldest clubs have British connections—even FC Porto's original name was "Football Club do Porto."

Tea Culture Catherine of Braganza introduced tea-drinking to the English court, transforming British culture forever.

Why Has It Lasted?

The Anglo-Portuguese Alliance has survived because:

1. Mutual benefit: Neither nation has gained from breaking it 2. Non-interference: Neither tried to dominate the other 3. Shared enemies: From Castile to Napoleon to Hitler, they've faced common threats 4. Trade: Commercial ties made peace profitable 5. Flexibility: The alliance adapted to changing circumstances

The Alliance Today

In 2022, the alliance was celebrated with state visits and commemorative events. Both governments regularly reference this "oldest alliance" in diplomatic communications.

While NATO and the EU provide the primary frameworks for cooperation today, the Windsor Treaty remains a powerful symbol of enduring friendship between two nations that have, for 637 years, remained allies.

Learning from History

For Portuguese learners, this history explains:

• Why English words appear in Portuguese (and vice versa)
• Why Portugal has such close ties to the Anglophone world
• Why port wine has English names
• Why football terminology in Portuguese often echoes English

The Treaty of Windsor isn't just a historical curiosity—it's a living document that continues to shape the relationship between two languages and cultures.

"There is between England and Portugal an ancient and unbroken friendship." > — Invoked by Winston Churchill, 1943