Apparently John Kirkpatrik was involved in a play about Boadicea:

"         SONG FOR A DARK QUEEN
by Rosemary Sutcliff. The Vic. Adapted and directed by Nigel Bryant.
Composed music, songs and dances for this dramatisation of the story of Boadicea. Extensive recorded score of fanfares with battle scenes, love songs and dances, and high ceremonial. Created a whole world of early British ritual, with Pagan carols and stylised fights. The dramatisation, by Nigel Bryant was published as a play, with all the music and songs, by Heinemann Books."

John Kirkpatrick's website