The anti-convict move had scarcely ended when the colony was once again involved in a war. The Xhosa bitterly resented Sir Harry Smith's recent annexation of their lands, and had secretly been preparing to renew their struggle ever since the last war. Sir Harry Smith, informed of the increasing Xhosa mobilisation, went to the border region and summoned Sandile and the other chiefs for a meeting. Sandile refused to attend the meeting, after which the governor declared him deposed from his chieftainship at an assembly of other chiefs in October 1850, and appointed an English magistrate named Mr Brownlee to be temporary chief of the Ngqika tribe. It seems that the governor believed that he would be able to prevent a war and that Sandile could be arrested without armed resistance. Colonel George Mackinnon, who had been sent out with a small army with the goal of arresting the chief, was attacked in a narrow gorge on 24 December 1850 by a large number of Xhosa gunmen. After some casualties, Mackinnon's men were driven back under heavy fire. This minor shoot-out prompted a general rising among the whole Ngqika tribe. Settlers in military villages that had been established along the border, were caught in a surprise attack after they had gathered to celebrate Christmas Day. Many of them were killed, and their houses set on fire.