Lady Maude le Strange, of Blakemere

There seems to be considerable confusion as to just which Maud Le Strange married Sir Brian Cornwall. History of Parliament Online claims she was the daughter of Fulk, 1st Baron Strange of Blackmere; but it is not clear that he had any daughter named Maud. A more traditional account is that she was the daughter of Roger, 4th Baron Strange of Knockin; but this does not account for Sir John Cornwall being his father's heir born in 1366.

Perhaps the true answer - this is nothing but a wild guess - is that the Black Death did away with Sir Brian's entire earlier family, and he was forced to remarry (we don't know whom) in order to get a surviving son and heir.