A cult of personality arises when an individual uses mass media, propaganda, or other methods, to create an idealized, heroic, and at times worshipful, image, often through unquestioning flattery and praise.

Mátyás Rákosi was so treated.

See also Stalin's cult of personality.

More information on the Wikipedia page [1], with a list of cults of personality at [2]. The Psychology Today article is [3].