William was a descendant of a family that had held a prominent position in Lincoln for two generations or more. John Gressington, a fishmonger who served as one of the city bailiffs in 1408-9, is probably to be identified as his grandfather, and it was very likely that another John, who was mayor in 1431-2, was his father. Between them the two Johns attested as many as 11 parliamentary elections for the city from 1411 to 1432.
Nothing further is known of Gressington’s career until the mid 1460s when he was once more pursuing several pleas in the central courts, in one of which he claimed that goods worth £20 had been taken from his tenements in Lincoln.
