By September 1900, the British were in control of both Republics, except for the northern part of Transvaal. They however found that they only controlled the ground their columns physically occupied. As soon as the columns left a town or district, British control of that area faded away. The huge territory of the Republics made it impossible for the 250,000 British troops to control it effectively. The vast distances between the columns allowed the Boer commandos considerable freedom to move about. The Boer commanders decided to adopt a guerrilla style of warfare. The commandos were sent to their own districts with the order to act against the British there whenever possible. Their strategy was to do as much damage to the enemy as possible, and then to move off and vanish when enemy reinforcements arrived.