He became Prior of the Irish Chapter of the Order of Knights Hospitaller, whose house was at Kilmainham, in 1356 and in the same year was appointed Lord Chancellor of Ireland; apart from a brief interval when he was replaced by Thomas de Burley, he served in both offices until at least 1359.
[3] It is also known that he played a major role in the Parliament held at Kilkenny in January 1359,[4] which was concerned largely with the threat to the Anglo-Irish from an apparently concerted series of attacks by neighbouring Irish clans.
[5] Several records of his tenure as Lord Chancellor survive: letters patent were issued by Edward III addressed to Frowyk and other Crown officials in December 1357, giving details of an inquiry into alleged misconduct by John de Boulton, the former Justiciar of Ireland, who held office briefly in 1357.
[4] A further entry in the Rolls explains that Parliament had decided to send Frowyk to England to make manifest to the King and Council the dangers which threatened his subjects in Ireland.
Roger de Frowyk, who built a mansion at Seething Lane, close to the Tower of London, around 1303, was a goldsmith and an English Crown official.