In the autumn of 1266 Henry III was bogged down at Kenilworth castle in Warwickshire, besieging the Montfortian garrison. While focused on crushing the revolt in England, the king also had other pressing business to attend to. While the siege was in progress, he agreed to the King of France’s suggestion for a truce with Navarre, to last for three years from Easter next.
Why a truce with Navarre? Theobald II, King of Navarre, had exploited the civil wars in England to invade Henry’s duchy of Gascony. The details of this little-known conflict have to be winkled out of Spanish-language essays (thank God for Google Translate). It is generally treated as a mere footnote in English histories of Henry’s reign, which is a pity. Henry, for one, didn’t regard it as such.
He and his heir, Lord Edward, had many causes of concern. One of Theobald’s allies was Richard de Montfort, a son of Earl Simon. A remarkably complete surviving record of the war, the Registro de Comptas, shows that Richard was very active in the Navarrese cause. As Theobald’s army advanced through Bigorre and Gascony, seizing towns and castles, Richard pops up all over the place. He appears to have served in the vanguard of the invading host, perhaps even in command.
There was another worry. Theobald requested military aid from his fellow kings of Aragon and Castile. Alfonso X of Castile had married his sister Eleanor to Henry’s heir, Lord Edward, to secure a permanent peace with England. The surviving evidence suggests he listened to Theobald’s overtures, and seriously contemplated knifing Henry in the back.
When Theobald invaded Gascony, his army was accompanied by several of Alfonso’s followers. These were the king’s notary, Master Fernando Garciá, Archdeacon of Niebla, who stayed with the army for forty days. Another was Alfonso’s half-brother, Don Luis. A payment is also listed to Alfonso’s porter, Garciá Pérez. Further payments are listed for the journey of two Navarrese envoys, Pedro López de Ezperun and Iñigo López de Larruz, to speak with Alfonso at Seville.
This was all very shady. Alfonso was supposedly Henry’s ally, and yet here he was, providing active support to the invasion of Gascony. To complicate matters, there was also a French interest. In the same year – 1266 – Alfonso started negotiations to marry his son, Fernando de la Cerda, to Blanche, daughter of King Louis of France. Theobald of Navarre had previously married Isabella, another of Louis’s daughters, so it appears Alfonso wished to have his cake and gobble it down too.
Fortunately for the English, Louis chose not to throw his weight behind the invasion. From a French perspective, it was far better to hold the contending powers in balance, than tip them one way or another. Hence, while at Kenilworth in August, Henry agreed to the French king’s request to broker a truce with Navarre. How much the English ever knew of Alfonso’s treachery is uncertain.
David Pilling is a novelist and historian and the author of Rebellion Against Henry III: The Disinherited Montfortians, 1265–1274 and the Champion series of novels, set in the Iberian peninsular of the late 13th century.