The oldest meanings are the same as they are today - inclined to peace, or characterised by peace. And this is the usual meaning in Shakespeare, where the word is used in this way 12 out of 13 times. When York asks why banished Bolingbroke's legs have "dared to march So many miles upon her peaceful bosom" (Richard II, II.iii.92), referring to England, he is describing a country untroubled by war. But in the next act, King Richard asks Scroop why Bushy and Green: "have let the dangerous enemy Measure our confines with such peaceful steps" (III.ii.124). This usage can make us pause. An enemy marching with peaceful steps seems to be a contradiction in terms. The problem is resolved when we realise that this is peaceful in the sense of "undisturbed, untroubled". The enemy is being allowed to pass unopposed.
David Crystal David Crystal is author, with Ben Crystal, of Shakespeare's Words, published by Penguin