Duncan's War by Douglas Bond
Young Duncan M'Kethe finds himself caught in the web of Sir James Turner, the former Covenanter turned military leader of the persecutors. Duncan is torn by his hatred of the English, who have treated his friends cruelly, and his father's instructions to love his enemies. He must be true to Jesus Christ while attempting to rescue his father from enemy hands.
The first in the Crown & Covenant series, this book emphasizes the sacrificial loyalty to biblical Christianity that so many of our Christian forbearers displayed. Recommended for ages 10 to 14.