The story follows the fortunes of the four Beverley children who are orphaned during the war, and hide from their Roundhead oppressors in the shelter of the New Forest where they learn to live off the land.
The story begins in 1647 when King Charles I has been defeated in the civil war and has fled from London towards the New Forest. Parliamentary soldiers have been sent to search the forest and decide to burn Arnwood, the house of Colonel Beverley, a Cavalier officer killed at the Battle of Naseby. The four orphan children of the house, Edward, Humphrey, Alice and Edith, are believed to have died in the flames. However, they are saved by Jacob Armitage, a local gamekeeper, who hides them in his isolated cottage and disguises them as his grandchildren.
Under Armitage's guidance, the children adapt from an aristocratic lifestyle to that of simple foresters. After Armitage's death, Edward takes charge and the children develop and expand the farmstead, aided by the entrepreneurial spirit of the younger brother Humphrey. They are assisted by a gypsy boy, Pablo, who they rescue from a pitfall trap.