A flick of Oscar Wilde here, a nod to Henry Kissinger there, a sprinkling of Charles Dickens here, a dollop of Abraham Lincoln and Theodore Roosevelt there. Job done!

The British monarch mobilised an elite squad of dead white men, leavened with humour and subliminal politicking, on Tuesday in a charm offensive aimed over Donald Trump’s head and squarely at the US Congress. Judging by the cheers and minute-long applause he received at the end, the soft power flex worked a treat and the special relationship lives to fight another day.

But the king’s central message – of two great nations entwined in destiny – was also an inadvertent reminder of two empires that look increasingly shabby these days with rightwing populists on the march and the ghost of the sex offender Jeffrey Epstein hovering in the shadows.

Charles became the first British king to address the Congress almost exactly 250 years after the US denounced his fifth great-grandfather as a tyrant and declared its independence. “You’ll be back,” predicted George III in Hamilton and yet cricket, damp and a lack of air conditioning never clinched the deal.

What would America’s founding fathers have made of seeing George III’s direct descendant speak to their successors? Donald Trump mused at the White House on Tuesday: “They might be absolutely shocked but probably only for a moment. Surely they would be delighted that the wounds of war healed into the most cherished friendship.”

Well, Thomas Jefferson, Benjamin Franklin and co would surely be more shocked to discover that they now have their own mad king in the White House. If Charles spots signs saying “No kings” on his travels, he shouldn’t take it personally.

The House of Representatives chamber was chock-full for the king’s speech. Vice-president JD Vance was applauded on his way in, followed by senators and cabinet members who took prime seats near the front.

At least some go weak-kneed at the whiff of royalty. At a British embassy garden party on Monday, Senator Ted Cruz of Texas gushingly introduced the king to his daughters. Maybe this explains why Republicans worship the wannabe monarch in the White House.

Others had a point to make. Adam Schiff of California posted on social media on Tuesday: “We have ignored and assailed the British to the point where we are at war with Iran, and without a friend to be found.”

But entirely predictably, the name Iran never’s passed Charles’s 77-year-old lips. Nor did Israel, nor immigration, nor climate, nor a bunch of other hot potatoes in the Trump era. Instead the king delivered an exquisitely measured masterclass in less-is-more, emphasising common bonds that long predate Trump and – hopefully! – will long outlast him.

Wearing a blue suit and grey patterned tie, Charles, accompanied by Queen Camilla, entered the chamber to rapturous applause at 3.06pm. It was the rarest sight and sound: Democrats and Republicans united, with Nancy Pelosi looking just as enthusiastic as John Thune. Even presidents don’t get such a welcome when they come here to deliver the State of the Union address.

When Charles began by expressing gratitude to Congress and the American people for “welcoming us to the United States to mark this semiquincentennial year of the declaration of independence”, the chamber erupted in cheers and a standing ovation on both the floor and in the public gallery – finally, here was a man who could make American feel good about themselves!

The king went on: “And for all of that time, our destinies as nations have been interlinked. As Oscar Wilde said, ‘We have really everything in common with America nowadays except, of course, language!’

There was deep, resonant laughter and Charles, with a wiggle of the eyebrows, looked pleased at how the quip had gone down. Moments later, he pushed the mirth button again with: “This is a city which symbolises a period in our shared history, or what Charles Dickens might have called A Tale of Two Georges.”

You had to be there.

“King George never set foot in America and, please rest assured, I am not here as part of some cunning rearguard action!” Another laugh. He was on a roll!

Charles said Magna Carta has been cited in at least 160 supreme court cases since 1789, “not least as the foundation of the principle that executive power is subject to checks and balances”. A dig at Trump’s authoritarian ambitions? Democrats did seem to applaud that one with special vim.

And when the king characterised Congress as “not by the will of one, but by the deliberation of many”, there was a shout of “All right!” from the Democratic side of the house.

Charles continued to make some discreet political jabs. He said he had served with “immense pride” in the Royal Navy – the same one that Trump has been disparaging lately.

The king went on: “In the immediate aftermath of 9/11, when Nato invoked article 5 for the first time, and the United Nations security council was united in the face of terror, we answered the call together.” It did not take a giant leap of imagination to see this as gentle chiding of the Nato-bashing Trump.

And when the monarch spoke of “unyielding resolve needed for the defence of Ukraine and her most courageous people”, the roar of approval in the chamber may have been jarring to the ears of the attendant Vance.

Charles is famously an environmentalist who talks to plants. We will never know if conversing with Trump reminded him of Audrey II, the man-eater from Little Shop of Horrors. But in his speech to Congress he did cite Teddy Roosevelt in speaking of the need to protect “the glorious heritage” of America’s natural splendour.

Mission accomplished, he departed the chamber with handshakes and smiles. Uneasy lies the head that wears a crown but, thanks to some canny speechwriting and a book of quotations, the king had hopefully made his point without triggering a fiery tirade from the mad monarch on Truth Social.