About 1418 he emerged as a leading opponent of the Lord Lieutenant of Ireland, John Talbot, 1st Earl of Shrewsbury.
Together with Christopher Preston, 2nd Baron Gormanston, he was accused of treasonable correspondence with Thomas Le Boteller, the Prior of the Order of Hospitallers at Kilmainham, imprisoned and threatened with forfeiture of his titles and estates.
No plausible evidence of treason was produced against either Kildare or Gormanston, and they were released and restored to their estates.
He has been identified as Richard FitzGerald of Ballysonan, who married into the Castlemartin family, and was the ancestor of the Baron of Dunsany.
The dispute was eventually resolved in favour of John's son Thomas FitzGerald, 7th Earl of Kildare.