Brookby was a lecturer in theology at Magdalen College, Oxford. He was well versed in Greek and Hebrew, and enjoyed a reputation as an eloquent preacher. In a sermon of Brookby's, he attacked the king's actions and mode of living.
He was arrested, put to the rack, and tortured in order to make him retract what he had said. Disabled as a result of his tortures, Brookby was cared for by a pious woman for a fortnight. By the command of the king, an executioner strangled him to death, with the Franciscan cord which he wore around his waist.
- Mary Jean Stone, Faithful unto Death (London, 1892), iv, 76;
- Anthony Parkinson, Coll. Anglo-Minor. (London, 1726), 239;
- Thaddeus, The Franciscans in England (London, 1898), III, 17;
- Danielle, Martirio e Morte d'alcuni Frati di San Francesco, III, 16.