An annexation policy applied by Lord Dalhousie (Governor-General, 1848 to 1856) under which a princely state would "lapse" to the British if its ruler died without a natural heir, with adopted heirs not recognised.
It is a named political cause of the Revolt of 1857 and a high-frequency Dalhousie-era fact, often paired with the states annexed under it.
Awadh was annexed for "misgovernment" (1856), not under the Doctrine of Lapse; the doctrine applied to states without a natural heir.
Dalhousie's policy annexing heirless states (no adopted heir recognised); a political cause of 1857.