Research Notes:

In 1369 John served under the Earl of Pembroke in Poitou and Anjou. The Earl’s forces of 300, having ravaged the estates fo the viscount de Rochechouart, returned to Poitou and stopped at the village of Puirenon. In the late afternoon they were attacked by French forces of 700 under command of Sir Louis de Sancere, marshal of France. More than 120 of Pembroke’s forces were killed or captured. The English retreated to a house with a stone wall. Surrounded, they held off multiple attacks by the French that day. That night they used to fortify the house, which allowed them to hold off the much larger French force all day. When the French heard that Sir John Chandos was marching with fresh soldiers in relief of the earl, they retreated..

In 1371 John was given a licence for an oratory at Merton for 2 years.

In Jun 1372 John left England with the Earl of Pembroke for Aquitaine, France.

On 23 Jun 1372 John was killed at a naval battle with a Spanish fleet off La Rochelle in the Bay of Biscay. The Earl of Pembroke had been appointed Governor and Captain of Poitou, and was enroute to La Rochelle and found the Spanish blocking the entrance. The fleet of Henry of Castile consisted of 40 large ships and 13 barks, all equipped for war. After a fierce battle and night fell each fleet separated and anchored. The next day, the battle continued with ships in close contact, and grappling hooks being used to board the English vessels. Four Spanish ships attacked the Earl's ship on which was 22 of his knights including John. The Earl was captured, and all his knights were either slain or captured. ²