Family and Situation
Sir Lewis is the deceased husband of Lady Catherine de Bourgh and the father of Anne de Bourgh.
We are told almost nothing about his situation, though we know that married he married the daughter of an earl and was prepared to put up with the antics of a young Lady Catherine Fitzwilliam. His widow later describes his family, like the Darcys, as being “respectable, honourable, and ancient—though untitled”. Given that he likely is just a baronet (since his daughter is untitled), his estate must have brought in significant funds if he was able to attract the daughter of an Earl.
Lady Catherine says at one point that she sees “no occasion” for entailing estates away from the female line as “It was not thought necessary in Sir Lewis de Bourgh's family.” This is likely meant to imply that no ancestor was worried about his children wastefully spending through the estate. On the other hand, it could also mean that the estate has not been very large for very long and no one has actually had an opportunity to set up an entail.