The Battle of Montiel (1369) was the final clash in Castile’s civil war, where Enrique of Trastámara defeated and killed his half-brother, Pedro the Cruel, ending a brutal dynastic conflict. (Miniature from Jean Froissart's "Chronicles".)
The road was dry, the wind harsh. Dust curled around the hooves of tired horses. Among the mercenaries and exiled lords rode a dark figure in battered armor, his face shaded by a heavy helmet, his eyes sharp and unreadable. He wasn’t tall or handsome, and he wasn’t born to rule. But Bertrand du Guesclin (~1320-1380), son of a minor Breton knight, was about to change the fate of a kingdom that wasn’t his.
This wasn’t France. This was Castile. And this wasn’t his war. But it would become his story.
A Kingdom Torn in Two
Castile in the 1360s was a land of ambition and betrayal. Two brothers claimed the throne.
The first, Pedro I, ruled from Toledo with an iron fist. His enemies called him Pedro the Cruel, and they had reason to. Rebellions were crushed. Rivals vanished. Allies were disposable. But Pedro had powerful friends abroad—especially the Black Prince, the heir to the English crown and commander of elite troops.
The second, Enrique of Trastámara, was his half-brother, born outside of marriage. He had no lawful claim to the throne, but plenty of noble supporters—and the backing of the French king. Enrique fled north to seek help. And France answered, not with armies, but with one man who could lead them all.
They sent du Guesclin.
The Breton and the Pretender
Bertrand du Guesclin was not a man of polish. People said he looked like a bear and fought like one too. He didn’t win battles with speeches or splendor—he won them with cunning and grit. He had clawed his way up through the ranks of France’s endless war with England, earning a fearsome reputation and a name: The Black Dog of Brocéliande.
In 1366, du Guesclin led a motley army across the Pyrenees. Mercenaries, outlaws, knights of fortune—they followed him not for glory, but because he got results.
The campaign began well. Soria, Burgos, and Toledo all opened their gates to Enrique. Pedro fled. For a moment, the road to power seemed open.
But the English weren’t far behind.
Disaster at Nájera
In 1367, the armies met near the town of Nájera. The Castilian sun beat down on the banners of France and England, as du Guesclin faced off against the Black Prince himself.
It was a slaughter.
Du Guesclin was captured. Enrique ran. Pedro, cruel as ever, returned to his throne.
But Pedro didn’t win the war. He lost the people. While Enrique rebuilt, Pedro grew more isolated, more hated. And du Guesclin? He was ransomed—and returned.
He always returned.
The End at Montiel
The final act played out two years later, in 1369, at the fortress of Montiel, where Pedro’s army, weary and thin, was surrounded. Du Guesclin led the siege.
One night, Pedro slipped from the castle, trying to escape. But he was caught and brought to Enrique’s tent.
What happened next has passed into legend.
Some say Enrique hesitated. Brother or not, this was murder. Others say he moved without blinking. Du Guesclin, watching the drama unfold, supposedly said:
"I do not kill kings… but I open the door."
And he did.
Pedro was dead. Enrique was king. And Castile, now ruled by a French ally, would never again stand with England.
Echoes on the Wind
Bertrand du Guesclin returned to France, where he rose even higher—commander of the French armies, hero of the reconquest. But Spain stayed with him, a strange land where he’d helped make a king.
If you walk today through Toledo’s stone streets, or climb to the ruined fortress at Montiel, or stand in the plaza of Burgos, listen. You might hear the low rumble of horses, the rasp of old armor, the voice of a knight who wasn’t meant to rule—but ruled the moment all the same.
Further Reading
Bertrand du Guesclin by Georges Minois
The Hundred Years War, Vol. II: Trial by Fire by Jonathan Sumption
The Black Prince by Michael Jones
La vie et les faits mémorables du très vaillant chevalier Bertrand du Guesclin by Cuvelier (14th century epic poem)
Local historical exhibits in Toledo, Montiel, and Burgos cathedrals