Question: One what date was the battle fought, that Simon Grundel-Helmfelt is most notable for?
Sentence (from "Battle of Nibley Green"): The Battle of Nibley Green was fought on 20 March 1469 (modern historians would date the battle in 1470 - prior to the adoption of the Gregorian calendar in England the start of the new year was 25 March; the battle being fought on 20 March meant it fell into the previous year), between the troops of Thomas Talbot, 2nd Viscount Lisle and William Berkeley, 2nd Baron Berkeley.
Relevant evidence: No