Ronald Reagan

Her Majesty and the late US president bonded over their love of horses, and were photographed riding at Windsor in 1982. The year after, the Queen and the Prince Philip visited Nancy and Ronald at their family ranch in California and spent a rainy day huddled around an open fire stoked with wood cut by the president.

In 1989, Reagan was even granted an honorary knighthood in recognition of his help to the UK in the Falklands War.