History
This royal role is acknowledged in the Preface to the Thirty-Nine Articles of 1562. It states that:
"Being by God's Ordinance, according to Our just Title, Defender of the Faith and Supreme Governor of the Church, within these Our Dominions, We hold it most agreeable to this Our Kingly Office, and Our own religious zeal, to conserve and maintain the Church committed to Our Charge, in Unity of true Religion, and in the Bond of Peace ... We have therefore, upon mature Deliberation, and with the Advice of so many of Our Bishops as might conveniently be called together, thought fit to make this Declaration following ... That We are Supreme Governor of the Church of England ... "
Article 37 makes this claim to royal supremacy more explicit:
"The King's majesty hath the chief power in this Realm of England, and other of his Dominions, unto whom the chief Government of all Estates of this Realm, whether they be Ecclesiastical or Civil, in all causes doth appertain, and is not, nor ought to be, subject to any foreign jurisdiction ... We give not to our Princes the ministering either of God's Word, or of the Sacraments ... but that only prerogative, which we see to have been given always to all Godly Princes in holy Scriptures by God himself; that is, that they should rule all estates and degrees committed to their change by God, whether they be Ecclesiastical or Temporal, and restrain with the civil sword the stubborn and evildoer ... The Bishop of Rome hath no jurisdiction in this Realm of England."

Church of Scotland