Question: Who is John Bourchier, 1St Baron Berners's maternal grandmother?
Sentence (from "John Bourchier, 1st Baron Berners"): He died in May 1474 and was succeeded in the barony by his grandson John Bourchier, 2nd Baron Berners, his son Sir Humphrey Bourchier having been killed at the Battle of Barnet in 1471.
Relevant evidence: No