Style of the British sovereign in the context of Act of Supremacy (Ireland) 1537

The Acts of Supremacy are two acts passed by the Parliament of England in the 16th century that established the English monarchs as the head of the Church of England; two similar laws were passed by the Parliament of Ireland establishing the English monarchs as the head of the Church of Ireland. The 1534 act declared King Henry VIII and his successors as the Supreme Head of the Church, replacing the Pope. This first act was repealed during the reign of the Catholic Queen Mary I. The 1558 act declared Queen Elizabeth I and her successors the Supreme Governor of the Church, a title that the British monarch still holds.

Royal supremacy is the legal sovereignty of the king as civil law over Church of England canon law.