Sir John Coleshill was the son of Sir John Coleshill, and died in the battle of Agincourt. He had a son, Sir John Coleshill, who died without producing children.
Joan Coleshill (my ancestor) is the daughter of Sir John Coleshill and the sister of Sir John Coleshill. The problem is, it is difficult to determine WHICH John Coleshill in the sequence is her father! Historical volumes discussing the family played very loose with their pronouns.
Just look at this, from "The Cornwall Register" (1847):
"His widow married Sir John Coleshill: their son, Sir John, was slain at Agincourt, leaving an infant son, Sir John, who died without issue. His only sister, Joanna..."
You can't throw out three generations of people with the same name in a single sentence, then expect the reader to know who the subject ("his") of the next sentence refers to!
From "Memorials of the Danvers Family":
"Sir John Coleshill, son of the above, was killed at the battle of Agincourt in the year 1415, leaving by his wife, daughter of Courtney, a son, on whose death without issue the estates passed to his sister Johanna..."
Again! Whose sister is she? Clearly not the first, but it could easily be the second or third.
Argh...