1919–1920 campaign was an incursion by the Mahsud Tribe. In 1919 the Waziris took advantage of unrest in Afghanistan following the Third Anglo-Afghan War to launch more raids against British garrisons. It has been asserted that one of the reasons for these raids was that a rumour had been spread amongst the Wazirs and the Mahsuds, that Britain was going to give control of Waziristan to Afghanistan as part of the peace settlement following the Third Anglo-Afghan War. Buoyed by this prospect and sensing British weakness, the tribes were encouraged to launch a series of large scale raids in the administered areas. The British Forces which included 51st Sikhs Frontier Force eventually restored calm.