of Gimingham, was for a considerable annual income of £20—it has been estimated that during the 15th century only 12,000 households in England had an income of between £10 and £300. Erpingham was with Lancaster during the English invasion of Scotland in 1385. Lancaster's determination to rule the Kingdom of Castile after his marriage to the Castilian princess Constance in 1371 dominated his life for 15 years. In 1386 Richard II of England agreed to release the funds needed for Lancaster to lead a Castilian campaign. Lancaster's royal status gave him a prominence in affairs of state that created tension between him and Richard, and the cost of the Castilian campaign was seen by the King's advisers as a price worth paying for the political freedom Richard would gain from Lancaster's absence. Erpingham was with Lancaster when his army set sail from Plymouth in July 1386. It landed at Brest, France, and temporarily relieved the besieged English garrison. After leaving Brest the army arrived at A Coruña, and went on to bring Galicia under English control. John I of Portugal joined with Lancaster in March 1387, but because of a lack of food for their animals, and the successful defensive tactics employed by the Castilians, their campaign was abandoned after six weeks. In 1388, Erpingham participated before Charles VI of France in a jousting tournament at Montereau, his adversary being Sir John de Barres. As related by the French chronicler Jean Froissart, half way through the tournament, Erpingham was struck violently on his shield by his opponent, and was knocked off his horse. Stunned by the blow, he managed to recover and continue the joust, "to the satisfaction of the king and his lords". Erpingham was sent back to England to watch over Lancaster's son Henry Bolingbroke and went into his service. In 1390 he was with Bolingbroke's retinue when it crossed the English Channel with the intention of joining Duke Louis II of Bourbon in a siege of the Tunisian port of Mahdia on a crusading expedition via Marseilles. The expedition was abandoned when Charles VI refused him permission to travel through France. Bolingbroke then went on a crusade in Lithuania. Erpingham, one of the most trusted and experienced of Lancaster's men, belonged to what the historian Douglas Biggs describes as "the 'adult' portion of Henry's force"—older men who were probably sent by Lancaster to guide and protect his