The English break with Rome began as a legal argument about jurisdiction rather than a dispute about doctrine, and that beginning marked the church that resulted. Henry VIII wanted his marriage to Catherine of Aragon annulled, the pope was unable or unwilling to oblige, and a series of statutes over several years transferred to the crown the powers previously exercised from Rome: first appeals, then the payment of revenues, then the appointment of bishops, and finally, in the Act of Supremacy of 1534, the headship of the church itself.
The act declares the king to be the only supreme head on earth of the Church of England, with authority to visit, reform and correct errors and abuses. It does not change a single article of doctrine. For most of Henry's reign the mass continued substantially as before, and men were executed for denying transubstantiation and for denying the supremacy in the same years.
Enforcement was by oath, and the oath is what made it lethal. Refusing to swear was treason. Thomas More, who had been Lord Chancellor, and John Fisher, bishop of Rochester, were both executed in 1535 for declining to affirm it, More having kept silent rather than argue. The dissolution of the monasteries followed, transferring an enormous quantity of land to the crown and from the crown to the gentry, which gave a great many families a material stake in the settlement.