[1][2] Son of Thomas B. of Grassington West Riding of Yorkshire William Dean attended schools in Leeds and Clitheroe.
[3] That same year he studied at the English College, Reims and was ordained priest at Soissons, 21 December 1581, together with the martyrs George Haydock and Robert Nutter.
He was banished with a number of other priests in early 1585, put ashore on the coast of Normandy, and threatened with death if he returned to England.
[4] Dean, who had been condemned with five other priests and four laymen, was the first to suffer on the gallows recently erected at Mile End.
His crimes included being reconciled to the Catholic religion, making his confession to Dean, and aiding and assisting the priest.
He was condemned for keeping a book called My Lord Leicester's Commonwealth and for having assisted William Dean.