It was exactly London's way of doing things to get the Crown to authorize a barrier, and then firmly remind the Crown that a barrier is there, and that Westminster is not London. As time goes on, the idea disguises itself in the pageantry of welcome.
When the Sovereign Anne Boleyn, Elizabeth, James or his grandson Charles comes to Temple Bar on his way from the Tower to Westminster for coronation or enters the City for other ceremony, it is all flowers and music and allegorical figures and conduits running wine.
When the Sovereign wishes to come into the City from Westminster, one or other of several successive Temple Bars, in wood or in stone, is there to make sure of his remembering that London is London, and that the rest of the world is not.
In time the idea crystallizes into a ritual. The gates are shut. The Sovereign must ask leave to come into his own capital.
Once he is inside, he is dutifully presented with the keys and the sword, but he is expected to give them back at once to the true monarch of this independent city, her Lord Mayor.
And though today there are no more gates to shut, there is no understanding the historic significance of Temple Bar without seeing it as the spot where London begins and Westminster, the Royal city, ends.