Jan Maria Michał Kowalski (1871-1942) was a Catholic priest – at least to begin with. Born in Latowicz, Poland, he was ordained in 1897, serving in several parishes before being assigned to the Capuchin church in Warsaw in 1900. A friend of his from seminary introduced him to a secret order of priests, the Congregation of Mariavites. This was organised around the private revelations of a nun, Maria Franciszka Kozłowska, who had begun having visions in 1893, centring around what she called “The Work of Great Mercy” (but quite different from St Faustina’s similarly named devotion).