The young lion will overcome the older one,
On the field of combat in a single battle;
He will pierce his eyes through a golden cage,
Two wounds made one, then he dies a cruel death.
In the summer of 1559 King Henry II of France (older one) lined up to joust Gabriel, Comte de Montgomery, (young lion), who was six years his junior. The tournament was held to celebrate the upcoming wedding of the king's daughter.
In their final pass, Montgomery's lance tilted up, burst through the king's poorly-secured visor (pierce his eyes through a golden cage), and splintered, according to "On the Death of Henry II."
In the Journal of Neurosurgery, Kamilah Dowling and James Goodrich write that the profusely-bleeding king remained conscious and was "able to walk up some steps with an unsteady gait."
But splinters from the lance had entered the king's eye, throat, and temple (two wounds made one). Despite the best efforts of royal surgeons, Henry II experienced agonizing pain, seizures, and partial paralysis (then he dies a cruel death) before dying in his bed 11 days later.
It all sounds pretty accurate, on the surface. But, according to "Nostradamus: The Illustrated Prophecies," the prophecy's veracity is in doubt because it didn't appear in print until 1614.