Dear Student,
a. The annexation of Awadh by the British was on the pretext of mis governance as Nawabs of the region mainly performed ceremonial roles.
b. The British in an effort to establish direct control over Awadh got control over the region under Doctrine of lapse ,as the British declared that the Nawab of Awadh, Wajid Ali Shah , was incompetent and was not capable of ruling resulting in poor governance.
c. It was thus, annexed by Lord Dalhousie under the policy of Doctrine of lapse in the year 1856.
Regards