A Time for War - Archibald the Grim Series, #3

The city of Berwick, stolen by the English, lies ripe for retaking. With the English King Edward away attempting to conquer France, Archie joins his cousin, the Lord of Douglas, in this perilous venture. But soon, King Edward returns, determined to take back Berwick and conquer Scotland once and for all. Faced with an invasion by a massive army, Archie and his comrades-in-arms must take desperate measures to save their homeland and their freedom.