We saw the portrait of Jean II le Bon a little earlier. Jean had great
difficulty against the English in the first years of the Hundred Years war,
but his successor Charles V and the great hero DuGuesclin won major victories
and even killed the fearless Black Prince -- a major blow to the Plantagenet's
claim to the French crown. When Charles V and DuGuesclin died in 1380,
the darkest days of the kingdom lay ahead. Charles the Sixth would be
known as Charles the Mad, and he would very nearly loose the kingdom entirely.
The helmet above belonged to Charles the Mad himself, and it's easy to see he
had trouble keeping his head about him. We may know these stories from
Shakespeare's plays, but Henry V of England was only too glad to take
advantage of this crisis in French leadership.