What is the meaning of [Pomp and circumstance]

An ostentatious display of ceremonial grandeur.

I’ve recently been watching a film of the Globe’s Theatre’s excellent production of Othello. Like most etymologists I suffer from a condition which causes an “I wonder where that came from” siren to hoot in my head whenever I hear an unusual phrase. Act III, scene III contains such a phrase – ‘pomp and circumstance’. I had previously only known that expression as the title of Edward Elgar’s Pomp and Circumstance Marches and I wondered if I might be able to add it to my list of phrases and sayings from Shakespeare. It turns out that I can, although, as so often with Shakespeare, the story isn’t completely straightforward.