Semayne's Case (1604) 5 Coke Rep. 91, is an English common law case reported by Sir Edward Coke, who was then the Attorney General of England. In the US, it is recognised as establishing the "knock and announce" rule.
Richard Gresham and George Berisford were joint tenants of a house in Blackfriars, London. Berisford died, leaving his effects, including some papers, to Peter Semayne. Semayne sued to have the effects delivered to him, so the Sheriff of London, with a valid writ, entered the house by breaking down the doors.
The holding of the case can best be summed by Coke's words,
|“||In all cases when the King is party, the sheriff may break the party's house, either to arrest him, or to do other execution of the K[ing]'s process, if otherwise he cannot enter. But before he breaks it, he ought to signify the cause of his coming, and to make request to open doors…||”|
The case is also famous for Coke's quote;
|“||the house of every one is to him as his castle and fortress, as well for his defence against injury and violence as for his repose.||”|
which became the popular proverb "an Englishman's home is his castle"
- 77 Eng. Rep. 195-6.
- 77 Eng. Rep. 195.