The Star Chamber (Latin: Camera stellata) was an English court of law which sat at the royal Palace of Westminster, from the late 15th century to the mid-17th century (c. 1641), and was composed of Privy Councillors and common-law judges, to supplement the judicial activities of the common-law and equity courts in civil and criminal matters. The Star Chamber was originally established to ensure the fair enforcement of laws against socially and politically prominent people so powerful that ordinary courts would probably hesitate to convict them of their crimes. However, it became synonymous with social and political oppression through the arbitrary use and abuse of the power it wielded.
In modern usage, legal or administrative bodies with strict, arbitrary rulings and secretive proceedings are sometimes called, metaphorically or poetically, star chambers. This is a pejorative term and intended to cast doubt on the legitimacy of the proceedings. 'Star Chamber' can also be used in its original meaning, for instance when a politician uses parliamentary privilege to attack a powerful organisation or person.
The first reference to the "star chamber" is in 1398, as the Sterred chambre; the more common form of the name appears in 1422 as le Sterne-chamere. Both forms recur throughout the fifteenth century, with Sterred Chambre last attested as appearing in the Supremacy of the Crown Act 1534. The origin of the name has usually been explained as first recorded by John Stow, writing in his Survey of London (1598), who noted 'this place is called the Star Chamber, at the first all the roofe thereof was decked with images of starres gilted', Gold stars on a blue background were a common medieval decoration for ceilings in richly decorated rooms, as still to be seen at Leasowe Castle, Wirral, the Scrovegni Chapel in Padua, and elsewhere.