The matching coat and dress, designed by Angela Kelly, the queen's senior dresser, were made in a cosy wool. It wasn't all pragmatism, though. That single organza frill on her coat was purely decorative, as were the dashing feathers on that hat.

But function is never far away in the monarch's choices. That brim was broad enough to keep the worst of any downpour at bay, but not melodramatically wide.

And, naturally, it was all richly emblematic. The outfit included allusions to her three jubilees as well as a reference to her distant ancestor Elizabeth I, who wore a Tudor, farthingaled version in the Ditchley portrait. Angela Kelly says that over the years the queen has taught her a huge amount about regal symbolism. The outfit was, apparently, a year in the planning.