Why revise historical interpretations?

Revision should not occur arbitrarily.

Good historical revision normally occurs because:

new evidence appears,

new documents are discovered,

old evidence is reinterpreted,

previous explanations fail to explain important facts.

Historians would distinguish this from political rewriting.

For example, if a government suppresses evidence and rewrites textbooks for ideological reasons, that is not the same thing as scholarly revision based on evidence.