Catch up: On Monday, Queen Elizabeth II welcomed Mr. Trump and his family to Buckingham Palace for a royal artillery salute and a state banquet. The president also continued a feud with London’s mayor, Sadiq Khan, who today described Mr. Trump as “the poster boy for the far-right movement around world.”

Photographs: See pictures from Mr. Trump’s state visit.

Background: Mr. Trump’s love affair with the royal family goes back to his mother, a Scottish immigrant who was enthralled by the queen. Our correspondent looked at the president’s interactions with the royal family.

Antitrust troubles grow for big tech

U.S. lawmakers said on Monday that they were looking into possible behavior by Silicon Valley giants that could lead to the first overhaul of antitrust rules in decades.

A House panel informed Amazon, Apple, Facebook and Google of its plans for a set of hearings, testimony from company executives and subpoenas for internal corporate documents.