John Sullivan was born into a wealthy Protestant family in 1861. He became barrister in London, travelled and lived a comfortable life until he converted to Catholicism when he was 35. After a few years of living simply and helping out in hospitals he entered the Society of Jesus in Ireland in 1900. As a priest he gained a widespread reputation for holiness, simplicity and for availability to anyone in need.
You can read more about John Sullivan, and arrangements for the forthcoming Mass, via this dedicated webpage.