King Charles III and Queen Camilla arrived in Washington, D.C., on Monday afternoon for a four-day state visit hosted by President Donald Trump. It is the first state visit by a British monarch to the United States since Queen Elizabeth II visited President George W. Bush in May 2007.

Why it matters: the visit tests whether personal diplomacy between Trump and the King can ease strained transatlantic ties at a time when the US-Iran war, trade tariffs, and defence commitments have driven a wedge between Washington and European allies.

The arrival

Trump and First Lady Melania Trump greeted the royal couple at the South Portico of the White House. The two couples held a private tea in the Green Room before touring the South Lawn’s newly expanded beehive and attending a garden party.

The visit proceeds despite the shooting at the White House Correspondents’ Dinner on Saturday evening, in which a 31-year-old gunman charged a Secret Service checkpoint and was subdued. Trump said he was “looking forward” to the King’s arrival.

Congress address

Charles is scheduled to address a joint meeting of Congress on Tuesday. He will be only the second British monarch to do so, after Elizabeth II spoke in 1991. The address is expected to celebrate the US-UK special relationship and mark the 250th anniversary of American independence.

Some Democratic members of Congress have signalled they may use the occasion to press the King on historical accountability, including Britain’s role in the transatlantic slave trade.

Diplomatic context

The visit arrives at a tense moment in the transatlantic relationship. Britain has sought to maintain distance from the US-Iran war while avoiding a public break with Washington. Trade remains another friction point, with US tariffs on British goods still in place despite years of negotiation.

Buckingham Palace described the trip as highlighting “historic connections and the modern bilateral relationship.” Analysts expect trade and pharmaceutical access to feature in private conversations between Trump and the King, though no formal agreements are anticipated.

The itinerary

The four-day programme includes a state banquet at the White House on Monday evening, the Congressional address on Tuesday, a visit to the September 11 Memorial in New York on Wednesday, and events in Virginia on Thursday. The King and Queen will also visit a community project in Harlem and attend an event marking the centenary of Winnie the Pooh.

Security across Washington has been tightened following Saturday’s shooting.