Government agents broke into John Entick's house and seized his papers under a warrant issued by the Secretary of State. The court ruled this was unlawful, establishing that government power must have legal authority and that every invasion of private property must be justified by law.

House of Lords held that local authorities must act reasonably and cannot ignore their fiduciary duty to ratepayers when setting wages, establishing early principles of Wednesbury unreasonableness.

This case established when prisoners have a right to an oral hearing before the Parole Board under common law fairness principles and Article 5(4) ECHR. The Supreme Court clarified that procedural fairness requires consideration of individual circumstances, not blanket policies denying hearings.

This early case established that the Crown cannot create new crimes or alter the law by proclamation alone, requiring parliamentary consent for changes to the common law.

House of Lords held that GLC's 'Fares Fair' policy of subsidising public transport through supplementary rates was ultra vires as it breached fiduciary duty to ratepayers.

The Case of Proclamations established that the King cannot create new law or change existing law through royal proclamation alone. This landmark case confirmed that royal prerogative powers are limited and cannot override statute or common law without parliamentary consent.

The House of Lords established that courts cannot inquire into Parliament's internal procedures when passing Acts, reinforcing the enrolled bill rule and parliamentary sovereignty.

The House of Lords established the fundamental principle that judges must not have any financial interest in cases they decide, creating the rule against pecuniary bias.

Court of Appeal established the fundamental principle that justice must not only be done but must manifestly be seen to be done.

Court of Common Pleas established that natural justice requires a hearing before a person is deprived of their property or rights, even where not expressly required by statute.

The Court of Appeal held that later Acts of Parliament impliedly repeal earlier conflicting provisions, establishing the doctrine of implied repeal in parliamentary sovereignty.

When Parliament provides a statutory scheme for government action, ministers cannot bypass it by relying on broader prerogative powers.

John MacCormick challenged the Queen's title as 'Elizabeth II' in Scotland, arguing Elizabeth I never reigned there. The Court of Session held that while courts cannot question the validity of Acts of Parliament, certain constitutional arrangements may be justiciable, though this particular claim failed.

This case established the famous 'Wednesbury unreasonableness' test for judicial review of administrative decisions. It set the standard that courts can only overturn administrative decisions if they are so unreasonable that no reasonable authority could have reached them.