Internet History Sourcebooks Project
Fordham University: Medieval Sourcebook: Inquisition
Article provides a detailed introduction to the inquisition as a legal proceeding rather than the Spanish relgio-secular institutional body that the word more often brings to mind.
University of Missouri
Famous Trials: The Trial of Galileo
An account of the trial of Galileo, who was brought before the Roman Inquisition in the early 1600s.
Wikimedia
Wikipedia: Medieval Inquisition
A Wikipedia article that reports on the Medieval Inquisition throughout Europe during the 12th and 13th centuries. Discusses the origin and history as well as the procedure of investigation, trial, torture, and punishment.
Rice University
Galileo Project: Historical Overview of the Inquisition
This article defines an inquisition, which is a legal proceeding of the Catholic Church and not restricted to a particular institution such as the Spanish Inquisition.