One of the most famous of the North American colonists actually lived here in London, for 16 years.

He's so famous that he's still on America's money.

Here is: hundred dollar bill, Benjamin Franklin.

This is his house in Craven Street, and every morning, he had quite a strange routine.

He'd come to this window, here, he'd open it up, and he'd take what he called an 'air bath'.

He'd let the air wash over him.

But he did it totally naked.

I don't know what the people across the road thought.

(lively classical music) Eccentric, yes.

But Franklin was also a shrewd political operator.

He was a media mogul.

He'd run one of America's most influential newspapers.

And when he arrived in London, he clearly made himself feel very comfortable.

Hello, come in.

Lucy: Thank you so much.

Welcome to Benjamin Franklin's house.

Thank you.

I'm here to see a replica of a game Franklin invented.

A sort of trick he used to play on people here in London.

What have you got in here, Henry?

So, here we have the magical picture game, otherwise known as, The Treason Game.

Essentially, the frame is electrified, so if you can see, the crown is metal, you're going to put your finger on it, say something critical about the King, and see what happens.

Okay... I don't like the King.

I want to steal his crown.

(electric zap) (screams) (laughter) How much electricity was that?

Um, who knows?

Franklin... -Who knows!

-Franklin... -You just tried to kill me!

Franklin wrote that it could potentially be fatal.

So, luckily, you weren't that treasonous.

You did survive.

But you got a nasty shock.

Yes, don't mess with George III, that's the message of this game.

Surprisingly, Franklin was really quite the royalist.

But that's not the only revelation.

Everyone thinks of Benjamin Franklin as American, but that's not really true, is it?

No, not at all, he was British.

And anyone who was living in the colonies was a British citizen.

And they considered themselves to be one of the counties abroad, basically.

When he comes to London, he has a portrait done, and he pretty much presents himself as a British intellectual.

He has a bust of Isaac Newton looking down at him whilst he's reading.

He's wearing a bright blue coat, with gold trimmings.

Something that would tell the viewer that this is a very important, wealthy individual.

So, he can dress to meet the circumstances?

He can.

He wasn't a huge fan of wigs, for example.

But when he has his portrait done in London, he's wearing a very fancy wig.

When Franklin was living here in this house in London, what was he doing?

He was sent over by the people of Pennsylvania, as a colonial agent, to represent their interests in Great Britain.

And the Pennsylvanians wanted more power to be moved to America.

Over time, Franklin then becomes a representative of Georgia, New Jersey, Massachusetts, and eventually, he adopts this sort of ambassadorial persona, he's essentially America's first ambassador, and he's representing all American interests in London.

He's actually a voice in the parliament, able to speak on behalf of North America.

He wasn't a great orator.

His power was in the pen.

So, he was writing lots of letters to influential people to try and keep the relationship between America and Britain as a strong one, and as a united one.

He's trying to keep that relationship going.

Like a marriage counsellor.

Very much so, yes.