Simplify the following text for a Grade 11 native English-speaking person.
Original: Childers ' state funeral in St. Patrick 's Cathedral , Dublin , was attended by world leaders including Nelson Rockefeller , Vice-President of the United States , Earl Mountbatten of Burma ( representing Queen Elizabeth II ) , Harold Wilson , the Prime Minister of the United Kingdom and presidents and crowned heads of state from Europe and beyond .
Simplified: Childers 's state funeral in St. Patrick 's Cathedral , Dublin , was attended by world leaders including the Earl Mountbatten of Burma ( representing Queen Elizabeth II ) , the Prime Minister of the United Kingdom and leader of the Opposition , and presidents and crowned heads of state from Europe and beyond .