Whitewashing

Whitewashing generally refers to the practice of hiding the historical existence or relevance of people of colour.

While in Regency London in 1814, Bill Potts was surprised at the amount of black people at the Frost fair, as this conflicted with what was often shown in movies she'd seen. The Twelfth Doctor explained to her that "history is a whitewash", citing Jesus Christ as a prominent example. (TV: Thin Ice)