A common name for heretics prior to the
Reformation; so called from the Albigeois, inhabitants of the district
which now is the department of the Tarn, the capital of which was Albi.
It was here the persecution of the Reformers began, under the direction
of Pope Innocent III, in 1209. The Waldenses rose after them, but are
not unfrequently confounded with them.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894