Unexpected monarch in bagging area? Queen Elizabeth pops down to Sainsbury's

LONDON, May 22 (Reuters) - Britain's Queen Elizabeth popped down to the supermarket on Wednesday to celebrate the 150th anniversary of the British high street chain, Sainsbury's.

The 93-year-old queen visited a pop-up replica of the original Sainsbury's shop which was founded on London's Drury Lane in 1869, selling just butter, milk and eggs.

She was greeted by Lord John Sainsbury, the great-grandson of the supermarket chain's founder John James Sainsbury, and was shown around replicas of old shop floors as they developed from the introduction of self-service shopping in the 1950s to the use of modern technology.

It was explained to her how shoppers now use self-service tills and pay using their mobile phones, although she did not try it out herself, and she also cut a commemorative birthday cake.

The pop-up Sainsbury's will be based in Covent Garden in central London for a week, giving visitors the chance to look at 150 years of history of the supermarket, Britain's second-biggest grocer. (Reporting by Michael Holden; editing by Stephen Addison)