<P> "While Shepherds Watched Their Flocks" is a Christmas carol describing the Annunciation to the Shepherds, with words attributed to Irish hymnist, lyricist and England's Poet Laureate Nahum Tate . </P> <P> The exact date of Tate's composition is not known, but the words appeared in Tate and Nicholas Brady's 1700 supplement to their New Version of the Psalms of David of 1696 . It was the only Christmas hymn authorised to be sung by the Anglican Church; before 1700 only the Psalms of David were permitted to be sung . It is written in common metre and based on the Gospel of Luke 2: 8 - 14 . </P>

Who wrote while shepherds watched their flocks by