Anyone still in any doubt about the lengths to which Queen Elizabeth II was prepared to go in the line of duty might consider the hideous company the role at times foisted on her. In 1991, she had to clink glasses with Zimbabwean dictator Robert Mugabe, and 20 years earlier had dined with Ugandan despot Idi Amin (though she later privately vowed to hit Amin with a sword if he dared to gatecrash her Silver Jubilee).