G. A. Henty 
Both Sides of the Border 

Classic historical novel. 'The four opening years of the fifteenth century were among the
most stirring in the history of England. Owen Glendower carried fire and slaughter among the Welsh marches, captured most of the strong places held by the English, and foiled three invasions, led by the king himself.’ According to Wikipedia: 'George Alfred Henty (8 December 1832 – 16 November 1902), referred to as G. A. Henty, was a prolific English novelist, special correspondent, and Imperialist born in Trumpington, Cambridgeshire, England. He is best known for his historical adventure stories that were popular in the late 19th century. His works include Out on the Pampas (1871), The Young Buglers (1880), With Clive in India (1884) and Wulf the Saxon (1895)’