Britain's Queen Elizabeth, who celebrates 60 years on the throne this year, will open in cooperation the London Olympics and Paralympics, Buckingham Palace and organizers said on Wednesday.
The third Olympic Games to be held in the British capital start on July 27 while the Paralympics opening rite at the similar stadium in east London will be in precisely six months' time on August 29.
The monarch also opened the Montreal Olympics in 1976 and her husband the Duke of Edinburgh opened the 1956 Melbourne Games on her behalf.
This, however, will be the primary time she has opened a Paralympics.
"The Paralympic Games will unquestionably be a time of strange pride for our nation, and it is fitting that Her Majesty will declare us underway," London 2012 chairman said in a declaration.
London before hosted the Olympics in 1908 and 1948 and will be the first city to stage the Games three times.
The Queen's father, George VI, opened the 1948 Games at the old Wembley Stadium and her great-grandfather Edward VII performed the honors at the now-demolished White City Stadium in 1908.