Christianity Today chronicles the history of clergy beards:
You’re more likely to see a beard in the pulpit today than at any time since the 1800s. But beards—especially among clergy—were once serious, symbolic matters. They separated East from West during the Great Schism, priests from laity during the Middle Ages, and Protestants from Catholics during the Reformation. Some church leaders required them; others banned them. To medieval theologians, they represented both holiness and sin. But historian Giles Constable says that rules on beards sound more forceful than they really were. Clergy (especially powerful ones) were likely to follow fashion in their day, too.
c. 195
Clement of Alexandria calls the beard “the mark of a man” and says “it is therefore unholy to desecrate the symbol of manhood.” Many other church fathers made similar remarks about beardly manliness. But most early church clergy were either beardless or had a closely trimmed beard.
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867
Reflecting growing tension between East and West, Pope Nicholas I writes to French bishops that Eastern church leaders were critical that “among us, clerics do not refuse to shave their beards.”
868
Eneas, bishop of Paris, writes Liber Adversus Graecos (Book Against the Greeks), and complains that Eastern leaders “accused the Latins and Romans because they shave their beards.”
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July 6, 1535
At his beheading, Sir Thomas More reportedly set his beard away from his neck on the chopping block. “My beard has not been guilty of treason,” he said. “It would be an injustice to punish it.”
1535
Henry VIII taxes beards.
1547
Archbishop of Canterbury Thomas Cranmer begins to grow a beard, ostensibly to mark his mourning of the death of King Henry VIII, but also to signal a break with the (beardless) Catholic clergy.