Section 17(5) of PACE 1984 abolished all powers of a Constable to enter under the common law with the specific exception (subsection 6) when dealing with or preventing a common law breach of the peace. This "offence" definition and power of arrest are contained under the common law definition of "breach of the peace". Breach of the peace powers are unusual in the fact they originate from the laws Alfred the Great consolidated into the common law approximately 1,000 years before the modern Constable was thought up. The first legislative reference to the common law breach of the peace was under the Justice of the Peace Act 1361. As a result, when a Constable uses their breach of the peace powers, they are acting as 'any person' and not fully as a sworn officer.