An Old Proverb
The proverb “those who live in glass houses should not throw stones” has been traced to the royal pedant James I. Seton says, “When London was for the first time inundated with Scotchmen, the Duke of Buckingham, jealous of their invasion, organized a movement against them, and parties were formed for the purpose of breaking the windows of their abodes. By way of retaliation, a number of Scotchmen smashed the windows of the duke’s mansion in St. Martin’s Fields, known as the ‘Glass House,’ and on his complaining to the king, his Majesty replied, ‘Steenie, Steenie (the nickname given to Villiers), those who live in glass houses should be careful how they fling stanes.’”
But the idea is more than two centuries older than the time of James I. It occurs in Chaucer’s “Troilus and Creseide,” where his use of verre, instead of glass, suggests that the proverb was originally current in Old French.