Knowledge of auto‐immune chronic active hepatitis (AI‐CAH) has developed since the 1940s. Using the analogy of the seven veils, the lifting of the first six could be represented by the finding of: hypergammaglobulinaemia; recognition of the clinical syndrome; the hepatic histopathology; the auto‐immune serological markers; the response to corticosteroid/immuno‐suppressive drugs; and the immunogenetic association with HLA B8; DR3. The lifting of the seventh veil, the ultimate understanding of AI‐CAH, will require the following: consensus on criteria for specifying auto‐immune hepatitis as an entity; identification of a liver‐specific auto‐antigen (or hepatocellular neo‐antigen) as target of the immune attack; the nature of the immune effector process which causes hepatocellular destruction; the basis of the deranged immunoregulatory processes expressed as decreased immune suppressor activity; and processes by which ‘anti‐immune’ drugs exert their ameliorative effects. Auto‐immune hepatitis is not unique in the paucity of data on these questions.