Henry II owed partially his throne to the French assistance during the civil war against his
half-brother Peter; at the same time English were occuping Castilian possesions in the Basque Country (a
payment for their own assistance to Peter) and an English nobleman, the Duke of Lancaster, claimed the
throne for his wife (daughter of Peter). So it is not strange if he signed an alliance with France, and
entered the Hundred Years War in the French side of the same one.
Henry sent a fleet, commanded by the Genoese Ambrosio Bocanegra, to attack the English at La
Rochelle, city besieged by French. Other Castilian commanders were Cabeza de Vaca, Fernando de Peón and the
Basque Ruy Díaz de Rojas. The English defending fleet was commanded by John of Hastings, count of
Pembroke. On June 22th 1372, both fleets clashed, with disastrous results for English.
Like in Winchelsea. Chronicles are also contradictory. Following
Froissart (a pro-English author) Castilian navy was surprised by English, but reacted and its bigger ships
managed to impose over the English, capturing a couple of ships. During the night, Pembroke tried to look
for help in the city, without success.
For the French De la Ronciere, Bocanegra took profite of the faster velocity if his ships, as
well as their lower draft, in order to make English ships run aground, and attack them later, capruting
all of them in an overwhelming victory.
Finally, the Spanish López de Ayala affirms the twelve Spanish ships attacked the English,
capturing Pembroke with all his knights and ships.
The victory was overwhelming: Pembroke was captured, with 400 knights and 8,000 soldiers. Even
more, in his return to Spain, Bocanegra captured 4 aditional English ships. He pardoned the life of all
the prisoners and sent Pembroke and his mayor knights to the presence of the king in Burgos.
Consequences of the battle. After this battle, a higher Castilian involvement in the war
marked a deccisive change in the operations: finished the English control of the sea, French could quicken
the "reconquest" of English possesions. England reacted with an alliance with Portugal, in order to
distract Castile, but the failure of this strategy forced it to sign the truce of Bruges, in 1375.