Brothers in Arms Book

It sounds like something from ancient mythology: three brothers living near the edge of a forest witness the coming of an invading army. They arm themselves, take to their horses and seek refuge in the woods they know as well as they know anything. The enemy arrives and systematically starts killing the long-oppressed minority to which the brothers belong. Horrified and angered, they lead guerrilla attacks against the enemy's installations and exact vicious revenge on local collaborators. Prompted by the eldest, who is selected as commander, the brothers and a growing numbers of warriors begin a campaign to save all their people, including the weak, the young, the old, the sick. Slowly the group evolves into a makeshift forest city with a hospital, workshops, a school and even a bathhouse. When the invading army retreats, the brothers emerge from the woods - the saviours of 1,250 people.