Complex sentence: Tate wrote the words to a number of hymns, of which the most widely remembered is the Christmas carol "As shepherds watched their flocks by night", and the libretto for Purcell's opera, Dido and Aeneas in 1689.
Split into simpler sentences: Tate wrote the words to a number of hymns, of which the most widely remembered is the Christmas carol "As shepherds watched their flocks by night". Tate also wrote the libretto for Henry Purcell's opera, Dido and Aeneas in 1689.