Hereditary bondsmen! know ye not
Who would be free themselves must strike the blow?

George Gordon, Lord Byron (1788–1824) English poet

Childe Harold’s Pilgrimage, Canto 2, st. 76 (1812)
    (Source)

Speaking of the Greeks, whose nation was still controlled by the Ottoman Empire. The lines were used by W. E. B. DuBois, along with a line from st. 74, as the epigraph of ch. 3 of The Souls of Black Folks (1903).