Mass of St. Secaire
A form of black mass originating in the Basque countryside,
possibly in medieval times. It was a travesty of a Christian mass
and was celebrated in a ruined church. The intention was not
to worship the devil but to direct currents of malevolent spite
against a victim. It may have had its origin in ancient folklore
practices.
Sources
Rhodes, H. T. F. The Satanic Mass. London, 1954. Reprint,
London Arrow, 1964.