- Vassal of King Pedro of Portugal, knight and ambassador to England.
- Vassal of King Fernando who gave him the castle and lands of Cascais, becoming 1st Lord of Cascais and Governor of that castle.
- Father of Sancho Gomes de Avelar, the young man to be given to Enrique II of Castile as hostage, according to a clause in the peace treaty of Santarém (1373). In the event, the young Sancho was hidden away and not handed over to the Castilian monarch. Fernão Lopes never mentions the actual name of the young man. He is always referred to as "the son of Gomes Lourenço de Avelar." [Fernando, ch. 84]
- As a consequence of not allowing his son to be handed over to Enrique II as hostage, Gomes Lourenço is exiled and his estates in Portugal are confiscated (1373).
Gomez Lourenço do Avellaar