On 9th May 1386 the Treaty of Windsor was signed between Portugal and England, uniting the two countries in a perpetual alliance.
It remains the oldest active alliance in the world.
In WW2 it would TWICE play a quiet but critical part in the allies' victory over the Axis, to the watching disbelief of Roosevelt and the Americans.
Here's how the treaty came about, was lost, almost got cancelled, then helped Britain in its darkest hour. /1 🧵 #history #histodons #portugal #uk
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1385 and John of Aviz is standing on a hill with 6,000 soldiers, asserting his right to be King of Portugal.
Unfortunately, at the bottom of that hill is is the King of Castile, with 30,000 Castilians, French, Aragonese and Italians who disagree.
Luckily, for John:
1) This is a REALLY steep hill to (potentially) die on
2) His enemies LOVE knights
3) He has crossbowmen
3) He has 200 battle-hardened English longbowmen.
Because the English have just pulled a Helms Deep /2
The English are there because In 1373 the Kings of Portugal and England signed a very early and vague version of the Treaty mentioned in the first post.
"Your enemies are my enemies. Forever."
John of Portugal had invoked it in hope as much as expectation. And yet...
...the English show up.
So when the Castilians and French decide to LARP the Battle of Crecy that day?
Well... /3
At the Battle of Aljubarrota, through the better generalship by John of Aviz, insane Portuguese bravery, and a LOT of bloody arrows King John wins a stunning victory and secures Portugal's place in Europe forever.
After? The Treaty of Windsor is signed.
It is now official.
The perpetual alliance between England and Portugal is proclaimed and affirmed. It will hold through centuries of warfare, Empire building by both nations and the Napoleonic wars. /4
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It's now 1927. The British Government secretly start debating dropping the Treaty. Britain is strong. Portugal isn't. Is it in Britain's interests?
Sir Austen Chamberlain oversees a report into its value.
It IS worth keeping he says:
1) Britain shouldn't break alliances just because it can. These things matter.
2) The Navy are worried about the French taking the Azores
3) That 'perpetual' bit made the lawyers he spoke to say "Oooh. VERY interesting" in a scary way /5
And so the Alliance survives. Just. Although the Portuguese don't realise it.
Then the Nazis show up. And Franco in Spain. And France falls.
Suddenly in 1940/41 the Anglo-Portuguese Alliance is one of the tiny threads on which British survival in the war hangs, because of Portugal's prime position in relation to Britain's suddenly vital strategic interests in the Atlantic (via the Azores) and the Mediterranean.
Portugal effectively controls naval and air access to both /6
Portugal's Prime Minister (but in reality right-wing dictator) is António de Oliveira Salazar. Salazar is NOT a nice man. But he's also a pragmatist and no fan of Hitler.
He also now finds himself stuck in the middle of a tug of war for control of this strategically vital geography and some of the world's richest tungsten mines.
He's also worried about Franco invading Portugal. Siding with the then-winning Germany would neutralise that threat.
But Britain is his historic ally... /7
Salazar's Portuguese government secretly approaches the British:
Assure us Britain would still honour the alliance if we're attacked by Spain or Germany. Assure us YOU will still honour our alliance, and in return Germany will NEVER get access to the Azores.
We'll resist pressure to cut you off everywhere, even though they're clearly winning. Not only that, we will lean on Franco to remain neutral as well. /8
The British agree. They inform the Portuguese they would honour the treaty if Spain or Germany attacked Portugal.
Despite enormous German pressure, the fragile balance in the Iberian peninsular holds.
When the US joins the war and discover's this fragile thread is all that's securing the Azores and allied access to the Mediterranean, they are shocked into disbelief that Britain is trusting in a 600 year old treaty.
To the point where they start plans to invade the Azores. /9
It takes FRANTIC diplomacy on the part of Churchill and the British Foreign Office to prevent the US from invading the Azores.
The Azores are key to the war in Europe,. the Americans insist. They're in bombing range of America. They cover the Atlantic air gap. They control the undersea cables.
Control them, you win the Battle of the Atlantic.
WE KNOW Say the British.
So please stop trying to fuck this up for us. /10
John Bull
discobeez