"O Sacred Head, Now Wounded" is a Christian Passion hymn based on a Latin text written during the Middle Ages. Paul Gerhardt wrote a German version which is known by its incipit, O Haupt voll Blut und Wunden.
The hymn is based on a long medieval Latin poem, Salve mundi salutare, with stanzas addressing the various parts of Christ's body hanging on the Cross. The last part of the poem, from which the hymn is taken, is addressed to Christ's head, and begins "Salve caput cruentatum." The poem is often attributed to Bernard of Clairvaux (1091-1153), but is now attributed to the Medieval poet Arnulf of Leuven (died 1250). The seven cantos were used for the text of Dieterich Buxtehude's Membra Jesu Nostri addressing the various members of the crucified body
The poem was translated into German by the Lutheran hymnist Paul Gerhardt (1607–1676). He reworked the Latin version to suggest a more personal contemplation of the events of Christ's death on the cross. It first appeared in Johann Crüger's hymnal Praxis pietatis melica in 1656. Although Gerhardt translated the whole poem, it is the closing section which has become best known, and is sung as a hymn in its own right. The German hymn begins with "O Haupt voll Blut und Wunden".
The hymn was first translated into English in 1752 by John Gambold (1711–1771), an Anglican vicar in Oxfordshire. His translation begins, "O Head so full of bruises." In 1830 a new translation of the hymn was made by an American Presbyterian minister, James Waddel Alexander (1804-1859). Alexander's translation, beginning "O sacred head, now wounded," became one of the most widely used in 19th and 20th century hymnals.