The Normans and the Gaels professed the same faith, though the organisation of the church differed in areas controlled by the Normans from those areas controlled by the Gaels. Henry VIII, the second son of Henry VII, ascended the throne of England in 1509 and during his reign religion became, for the first time, a major cause of strife and division in Ireland.

In 1533 Henry VIII married Anne Boleyn and rejected the authority of the Pope who had refused to allow him divorce Catherine of Aragon. As a result the Roman Catholic Church was no longer acceptable to him. Henry regarded loyalty to Rome as disloyalty to his own authority.