Complex sentence: Henry's son, Henry V of England, wore this ruby in the crown he wore around his helmet at the Battle of Agincourt, a bejewelled gold fleuron was struck from this same crown during the battle and lost.
Split into simpler sentences: Henry's son, Henry V of England, wore this ruby in the crown he wore around his helmet at the Battle of Agincourt. During the battle a bejewelled gold fleuron was struck from this same crown and lost.