Richard Gernon, High Sheriff of County Louth, was murdered in 1311, a casualty of a long-running feud between the Gernouns and the prominent Brisbon family of Dundalk.
Our first record of John is his petition of 1320 to King Edward II of England to have the fishery of Gernonstown, from the river to the sea, granted to him for life.
[4] In the intervals he acted as attorney for the great heiress Elizabeth de Burgh, 4th Countess of Ulster, who had inherited her father's estates at an early age.
[1] Her mother Maud of Lancaster, a cousin of King Edward III, had considerable influence at Court, and Gernoun benefited from her patronage.
In 1345 one John de la Pulle, accused of assault by Margery Poe, complained that due to Gernoun's misconduct (described as the "intervention of error"), he could not get justice.
[7] Gernoun's successor as Chief Justice, Thomas de Dent, was ordered to make a full inquiry and report to the Justiciar of Ireland.