Rosemary Sutcliff 
Song For A Dark Queen 

From the day Cadwan fashioned a sword from a willow wand and composed a victory song for his young mistress, Boudicca, he has loyally charted her rise to Queen. Boudicca is the strong and brave leader of the Iceni tribe – courageously guiding her people from one victorious battle to her next. Then Emperor Nero rules that the royal line of the Iceni is to be ended, and Boudicca knows this is one battle she cannot afford to lose . . .