Six hundred British cavalry rode into a valley of Russian guns at Balaclava in 1854 because of a confused order. Tennyson wrote his poem weeks later, honoring their courage while acknowledging the blunder. The dactylic rhythm drives forward like a charge; the repetitions (theirs not to reason why) become liturgical. The poem is propaganda for heroism, and it works: the brigade's doomed ride has become a permanent image of noble futility. Tennyson knew what he was doing. The poem still does it.