- Standard-bearer to John of Gaunt, Duke of Lancaster, and "alferes do duque de Lencastre", in Fernão Lopes's words. [Fernando, ch. 128: 55]
- Accompanied Edmund, Earl of Cambridge, in his expedition to Portugal (1381) to assist King Fernando of Portugal in his third war against Castile.
- Also referred to by Fernão Lopes as "mõsery Thomas Symõn" .[João1, ch. 82]
- Accompanied John of Gaunt in his expedition to the Iberian Peninsula to claim the crown of Castile in the name of his wife, Constanza.
- Bibl: Anthony Goodman, John of Gaunt: the Exercise of Princely Power in Fourteenth-Century Europe (London: Longman, 1992), p. 114 and 215.
Thomas Symõn
Tomas Symom
Tomas Simom
Thomas FitzSimond
Chronicle entries in which Thomas Symond appears:
Crónica de D. João I, part 2, ch. 83