What does 'not the least' mean?

Hello everyone,

I’d like to know what ‘not the least’ means in the sentence below:

In her later poems, Phyllis Wheatley’s blending of solar imagery,
Judeo-Christian thought and figures, and the images borrowed from ancient
classicism suggests her range and depth of influences, not the least of which
is her African heritage

Many thanks. :slight_smile:

It is not the least important influence; in fact, the influence of her African heritage is considerable.

Thank you very much, Mr Micawber.