Breach of the peace
Constitutional law 
In the United States, the Speech or Debate Clause of Article One of the United States Constitution provides that members of Congress shall be immune from arrest in going to and departing from sessions and while Congress is in session except for cases of "Treason, Felony, and Breach of the Peace."
The first two are somewhat self-explanatory; it has been suggested that the third is deliberately somewhat vague. The doctrine thus established is called congressional immunity; it arose out of the necessity to prevent a vengeful executive from arresting members of the legislature under a pretext to prevent them from taking actions that the executive might find to be displeasing. In recent years, this doctrine has been used to prevent members from being stopped and held for speeding on their way to sessions; this apparently is not a "breach of the peace", whereas perhaps another misdemeanor such as "drunk and disorderly" might be construed to be such.
Most states of the United States and most other English-speaking jurisdictions have extended this privilege to members of their legislatures on the theory outlined above.
Public order 
England and Wales 
In England and Wales, theoretically all criminal offences cognizable by English law involve "a breach of the Queen's peace", and all indictments formerly concluded "against the peace of our Lady the Queen, her crown and dignity" before the passage of the Indictments Act 1915 and the Rules that formed that Act's first schedule. The conclusion has also found its way into constitutional law in many United States state constitutions, which mandate that indictments within the state end in a similar manner to the above, usually omitting the "crown" part or substituting "government". For example, New Jersey's is "against the peace of this State, the government and dignity of the same".
Historically that concluding phrase, now legally superfluous, represents the last trace of the process by which the royal courts assume jurisdiction over all offences, and gradually eroded the jurisdiction of the sheriff and of lords of manor and franchises, making crime a matter of national concern as distinguished from civil wrongs or infractions of the rights of local magnates. The Peace of the King was sworn on his accession or full recognition, and the jurisdiction of his courts to punish all violations of that peace was gradually asserted. The completion of this process is marked by the institution of the office of Justice of the Peace.
In England, Wales and Northern Ireland, breach of the peace is descended from the 1361 Justices of the Peace act, which refers to riotous and Barratory behavior that disturbs the peace of the King. More modern authority defines a breach of the peace as existing whether harm is actually done, or is likely to be done, to a person or his property, or a person is in fear of being harmed through an assault, an affray, a riot, an unlawful assembly, or some other form of disturbance.
The power to arrest for a breach of the Peace is usually used to remove violent, potentially violent or provocative offenders (it is not necessary for the offender himself to be physically involved in any violence) from a scene rapidly, in Bibby V Chief Constable of Essex it was also used when a person in the opinion of a Constable was likely to be the victim of a breach of the peace or an act of violence.
In England and Wales, breach of the peace is not an offence, in the sense that it is not punishable either by a fine or imprisonment either at statute or common law and nor do proceedings for breach of the peace give rise to any conviction. In England and Wales, constables (or citizens) are permitted to arrest a person to "prevent a further breach of the peace" which allows for the police or the public to arrest a person before a breach of the peace has occurred. This is permitted when it is reasonable to believe should the person remain, that they would continue with their course of conduct and that a Breach of the Peace would occur.
The only immediate sanction that can be imposed by a court for breach of the peace is to bind over the offender to keep the peace: that is, justices of the peace can require a person to enter into a recognizance to keep the peace. Any punishment (in the sense of a loss of freedom or permanent financial penalty) takes the form of loss of the surety if the defendant fails to keep the peace or be of good behaviour during the period for which he is bound over. The binding over itself does not amount to a conviction (but any following behaviour causing loss of the surety might well result in conviction for an associated offence). A failure to enter into a recognizance may of itself lead to a person being committed to custody under s.115(3) Magistrates Court Act 1980.
There are major differences between English law and Scots law with respect to dealing with breach of the peace; unlike England and Wales where criminal penalties apply to the behaviour leading to or liable to cause a breach of the peace, it is a specific criminal offence in Scotland which is prosecuted daily in the Sheriff Courts and due to its common law definition it can be applied to a number of scenarios. The maximum punishment if a case is remitted to the High Court remains imprisonment for life although such severe punishment is now rarely applied, usually being associated with breaches of licence during an existing life sentence.
The Scots Law definition of a breach of the peace is "conduct severe enough to cause alarm to ordinary people and threaten serious disturbance to the community."
A constable may arrest any person, without warrant, who commits a breach of the peace. A member of the public may not arrest a person for behaviour which amounts to no more than a breach of the peace (i.e. an arrest is not always for the offence for which someone is eventually prosecuted but can be for a more serious crime that appears to be occurring).
Breach of the peace can include, but is not limited to, any riotous behaviours (which includes 'rowdiness' or 'brawling') and any disorderly behaviour. This behaviour doesn't have to be noisy but still of a nature that would cause concern to other people. Examples include 'Peeping Tom'-type behaviour, persistently following someone, delivering 'threatening' letters and 'streaking' or 'mooning'.
To prove a Breach of the Peace the most important things to prove is that someone was Alarmed, Annoyed or Disturbed by the incident.
This offence can take place anywhere i.e. a house, a public street, a private office or any public space.
United States 
Cox v. Louisiana was a United States Supreme Court decision that held that a Louisiana statute criminalizing breaches of the peace "as authoritatively interpreted by the Louisiana Supreme Court is unconstitutionally broad in scope." The statute read in part:
Whoever with intent to provoke a breach of the peace, or under circumstances such that a breach of the peace may be occasioned thereby ... crowds or congregates with others ... in or upon ... a public street or public highway, or upon a public sidewalk, or any other public place or building ... and who fails or refuses to disperse and move on ... when ordered so to do by any law enforcement officer of any municipality, or parish, in which such act or acts are committed, or by any law enforcement officer of the state of Louisiana, or any other authorized person ... shall be guilty of disturbing the peace.
See also 
- Constitutional economics
- Rule according to higher law
- Disturbing the peace
- Disorderly conduct
- R. v. Howell  QB 416
- R. v. County of London Quarter Sessions Appeals Committee, ex parte Metropolitan Police Commissioner  1 KB 670, per Lord Goddard, CJ; Williamson v. Chief Constable of West Midlands Police  1 WLR 14, per Dyson, LJ)
- Smith v Donnelly 2002 J.C. 65 or 2001 S.L.T. 1007 or 2001 S.C.C.R. 800 (Confirmed with full bench decision in Jones v Carnegie 2004 S.L.T. 609 or 2004 S.C.C.R. 361)