The name Black Rod derives from the ebony staff, topped with a golden lion, that the official uses to knock three times on the door. Besides ceremonial duties, the British parliament website says the Black Rod is responsible for controlling access to and maintaining order within the upper Lords chamber. Clarke, replacing David Leakey who retired, said she was "both deeply honoured and delighted" when her appointment was announced last year.
"The House of Lords is a place where the smallest detail is as important as the big picture and the depth of heritage and tradition is second to none," she said. Clarke was presented with the ceremonial ebony staff last week by Queen Elizabeth II at Buckingham Palace.