John Stanley was a soldier and ambitious politician. In addition to accompanying Richard II to Ireland, he also served as justiciar of Ireland between 1389 and 1391. Beyond his political associations, Stanley is a possible candidate for the patron of the poet (or even the poet himself) who produced Sir Gawain and the Green Knight.
Michael J. Bennett, "Stanely, Sir John," in Oxford Dictionary of National Biography
Andrew Breeze, "Sir John Stanley (c. 1350-1414) and the Gawain-Poet," Arthuriana 14, no. 1 (2004): 15-30.
Gervase Mathew, The Court of Richard II (London: John Murray, 1968): 166. [This seems to be the first articulation of Stanley as the Gawain poet's patron.]
Tim Thornton, "Lordship and Sovereignty in the Territories of the English Crown: Sub-kingship and Its Implications, 1300-1600," Journal of British Studies 60 (2021): 848-866.
Margaret K. Smith