"presentation at St James's"
St James's Palace and surroundings in 1763
Public DomainSt James's Palace and surroundings in 1763 - Credit: Thomas Bowles

 Since Mr Lucas distinguished himself during his mayoralty and was knighted by the King, he went to the royal St James's Palace in London to receive his title.  

St James's Palace now
GNU Free Documentation LicenseSt James's Palace now - Credit: ChrisO, Wikipedia Commons

The building, which still stands, ceased to be used as a royal residence not long after the death of Jane Austen.