When Donald Trump meets Queen Elizabeth II next week, he will become the 12th U.S. president whom the monarch has met during her 66 years on the throne, the longest in British history.

Apart from Lyndon Johnson, Elizabeth has met every U.S. leader since Harry S. Truman, but no other U.S. presidential encounter has generated the same level of opposition and controversy in Britain as Trump's trip.

Prime Minister Theresa May offered Trump a state visit — a pomp-laden affair usually featuring an open-top carriage trip through central London and a banquet at Buckingham Palace — when she became the first foreign leader to visit him after his inauguration in January 2017.