Austen and her family leave Bath and move into a rented house in Castle Square between 1806 and 1809. 

In 1806, Janes's older brother, Francis Austen, married Mary Gibson. Since Francis was a naval officer and was often away at sea, he said that Mary and his mother, along with Jane, Cassandra, and Martha Lloyd, should share a house together in Southampton. Southampton was surrounded by picturesque countryside and was also close to Portsmouth, where Francis was stationed, so he could return and stay in Southampton often. Portsmouth is also the naval town where the main character of Mansfield Park, Fanny's, immediate family lives.  

Jane had been to Southampton twice before, once to attend school with her sister and cousin when she was only seven years old (until they all became ill and were taken home), and again when she was eighteen and stayed with her cousin Elizabeth, whose new husband was the Southampton Sherriff. 

("Jane Austen in Southampton." Jane Austen's World, janeaustensworld.com/2011/06/
     15/jane-austen-in-southampton/. Accessed 14 Nov. 2022.)