- Sir Thomas Percy (1344-1403 ), 1st earl of Worcester.
- Younger brother of Henry Percy, 1st earl of Northumberland (1341-1408), and uncle of Sir Thomas Percy the younger (1366-1387), who died during John of Gaunt's Peninsular campaign.
- Nephew of Henry Grosmont, 1st Duke of Lancaster.
- Signed indenture to serve as captain in John of Gaunt, Duke of Lancaster's Peninsular expedition to claim the crown of Castile in the name of his wife Constanza (1386). [João2, ch. 83]
- Admiral of Gaunt's fleet and key negotiator of treaties with Castile during Lancaster'd Peninsular campaign (1386-1388).
- Bibl: Anthony Goodman, John of Gaunt: the Exercise of Princely Power in Fourteenth-Century Europe (London: Longman, 1992), pp. 117, 120, 204, 282; Peter Russell, English Intervention in Spain and Portugal in the time of Edward III and Richard II (Oxford: Oxford University Press, 1955), pp. 421, 437, 521
Tomas Persy