|John Parker, 1st Earl of Morley|
John Parker, 1st Earl of Morley, was only son of John Parker, 1st Baron Boringdon, and his second wife the Honourable Theresa Robinson, daughter of Thomas Robinson, 1st Baron Grantham. He held the title 2nd Baron Boringdon, until the title Earl of Morley was created for him in 1815.
Baron Boringdon and his wife were firm supporters of inoculations and had John inoculated against small pox at a young age. This was something that John tried to present to House of Lords legislation that help stop the spread of small pox with vaccinations but was forced to back down.
It is safe to say that Jane would have been fully aware of the Earl of Morley. Their lives seemed to have bumped into the others multiple times. This wonderful article that was in Persuasions #14 in 1992: Lady Morley and the "Baron so Bold" by Chris Viveash.
His second wife, Frances Talbot was a close friend of Jane Austen.
It has been suggested that it was through this connection that Jane had information about life at court and the influence for Mr. Darcy.
Some more reading:
John Parker of Saltram, 1st Earl of Morley (1772-1840) - Regency History
Austen & the Countess of Morley: on Emma - Reveries Under the Sign of Austen
Jane Austen Quote of Week 192 - Becoming Jane Fansite